TypeError: undefined is not an object (evaluating i.subscribeTo()') plugin.js: 9

**Describe the bug**
When calling fcm.subscribeTo(..) the mentioned exception is thrown, only on iOS, on Android works as expected

**To Reproduce**
> import { FCM } from "@capacitor-community/fcm";
> var fcm;
> try {
> fcm = new FCM();
> } catch (e) {
> console.error(e);
> }
> try {
> PushNotifications.requestPermission().then(async (result) => {
> if (result.granted) {
> console.log("registering push notifications");
> await PushNotifications.register();
> }
> });
> } catch (e) {
> console.error(e);
> }
> try {
> await fcm.subscribeTo({ topic: "all" }); <--- here it crashes
> if (user) {
> await fcm.unsubscribeFrom({ topic: "not_logged" });
> await fcm.subscribeTo({ topic: "logged" });
> await fcm.subscribeTo({ topic: user.uid });
> } else {
> await fcm.subscribeTo({ topic: "not_logged" });
> await fcm.unsubscribeFrom({ topic: "logged" });
> }
> } catch (e) {
> console.log(fcm);
> console.error(e);
> }

From what i can see inot the source code, FCMPlugin is undefined

"@capacitor-community/fcm": "^1.1.2",
"@capacitor/core": "^2.4.7",
"@capacitor/ios": "^2.4.7",

**Expected behavior**
fcm.subscribeTo({topic: "all" }) should work and subscribe user to the "all" topic

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Desktop (please complete the following information):**
- OS: MacOS 11.5.2
- Browser safari
- Version 14.1.2

**Smartphone (please complete the following information):**
- Device: Iphone 7 Plus
- OS: iOS 14.7.1
- Browser safari
- Version ?

**Additional context**
Add any other context about the problem here.

Start at plugin.js:9 and trace the FCMPlugin entry point used by fcm.subscribeTo() on iOS. Reproduce with @capacitor-community/fcm 1.1.2 and Capacitor 2.4.7 on the stated iOS environment; done means subscribing to the all topic succeeds without the TypeError.

Written by the indexing model from the issue text.