diff --git a/signature-extension/background.js b/signature-extension/background.js
index 14ac54c..43a3a8f 100644
--- a/signature-extension/background.js
+++ b/signature-extension/background.js
@@ -28,7 +28,8 @@ async function syncAccounts() {
     try {
       let signature = await getUserSignature(syncable);
       let account = await browser.accounts.get(account_id);
-      await browser.signatureApi.setSignatureHTML(account.identities[0].id, signature);
+      let identity = {signature: signature, signatureIsPlainText: false};
+      await browser.identities.update(account.identities[0].id, identity);
       syncable.lastSync = new Date();
       syncable.lastError = null;
     } catch (error) {
diff --git a/signature-extension/changelog.html b/signature-extension/changelog.html
index 204e244..4efb5b1 100644
--- a/signature-extension/changelog.html
+++ b/signature-extension/changelog.html
@@ -15,6 +15,14 @@ <h1>Welcome in the new version of Signature sync for Gmail!</h1>
       only on first use and major changes, but you can always access it in add-on's preferences.
     </p>
 
+    <h2>Version 2.1.0</h2>
+    <ul>
+      <li>
+        Moving into official identity API in Thunderbid, as so the extension doesn't need the full
+        permissions anymore. <i>Requires Thunderbird 91 or newer.</i>
+      </li>
+    </ul>
+
     <h2>Version 2.0.0</h2>
     <ul>
       <li>
diff --git a/signature-extension/implementation.js b/signature-extension/implementation.js
deleted file mode 100644
index 4bf8f78..0000000
--- a/signature-extension/implementation.js
+++ /dev/null
@@ -1,23 +0,0 @@
-var { ExtensionCommon } = ChromeUtils.import("resource://gre/modules/ExtensionCommon.jsm");
-var { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
-
-var signatureApi = class extends ExtensionCommon.ExtensionAPI {
-  getAPI(context) {
-    return {
-      signatureApi: {
-        getSignature: async function (identityId) {
-          let signature = await Services.prefs.getStringPref(
-            `mail.identity.${identityId}.htmlSigText`,
-            null
-          );
-          return signature;
-        },
-
-        setSignatureHTML: async function (identityId, signature) {
-          Services.prefs.setStringPref(`mail.identity.${identityId}.htmlSigText`, signature);
-          Services.prefs.setBoolPref(`mail.identity.${identityId}.htmlSigFormat`, true);
-        },
-      },
-    };
-  }
-};
diff --git a/signature-extension/manifest.json b/signature-extension/manifest.json
index 1d87f3c..2cb0611 100644
--- a/signature-extension/manifest.json
+++ b/signature-extension/manifest.json
@@ -1,7 +1,7 @@
 {
   "manifest_version": 2,
   "name": "Signature sync for Gmail",
-  "version": "2.0.2",
+  "version": "2.1.0",
   "author": "Kamil Mańkowski",
   "description": "Sync your signatures with Gmail accounts",
   "homepage_url": "https://thbrd-signature.kam193.eu/",
@@ -11,7 +11,7 @@
   "applications": {
     "gecko": {
       "id": "signature-sync@thunderbird.extensions.kam193",
-      "strict_min_version": "78.4.0"
+      "strict_min_version": "91.0"
     }
   },
   "background": {
@@ -21,6 +21,7 @@
     "accountsRead",
     "identity",
     "storage",
+    "accountsIdentities",
     "*://www.googleapis.com/*",
     "*://oauth2.googleapis.com/*"
   ],
@@ -28,15 +29,5 @@
     "page": "options.html",
     "open_in_tab": false,
     "browser_style": true
-  },
-  "experiment_apis": {
-    "signatureApi": {
-      "schema": "schema.json",
-      "parent": {
-        "scopes": ["addon_parent"],
-        "paths": [["signatureApi"]],
-        "script": "implementation.js"
-      }
-    }
   }
 }
diff --git a/signature-extension/schema.json b/signature-extension/schema.json
deleted file mode 100644
index ee76bfa..0000000
--- a/signature-extension/schema.json
+++ /dev/null
@@ -1,38 +0,0 @@
-[
-  {
-    "namespace": "signatureApi",
-    "functions": [
-      {
-        "name": "getSignature",
-        "type": "function",
-        "description": "Get signature value or null",
-        "async": true,
-        "parameters": [
-          {
-            "name": "identityId",
-            "type": "string",
-            "description": "ID of identity tu update"
-          }
-        ]
-      },
-      {
-        "name": "setSignatureHTML",
-        "type": "function",
-        "description": "Set and enable HTML signature",
-        "async": true,
-        "parameters": [
-          {
-            "name": "identityId",
-            "type": "string",
-            "description": "ID of identity tu update"
-          },
-          {
-            "name": "signature",
-            "type": "string",
-            "description": "A string of signature (HTML)"
-          }
-        ]
-      }
-    ]
-  }
-]