Unable to display url content in iframe

I’ve a url which I’m sanitising using sanitizer and then binding the url variable dynamically on my iframe.
Below is my code:

.ts file

this.filePath = 'https://ionicframework.com/docs/';
    this.trustedUrl = sanitizer.bypassSecurityTrustResourceUrl(this.filePath);

.html file:

<iframe id="articleFullView" [src]='trustedUrl'  [hidden]="viewSelector"></iframe>

When I hardcord the url on the iframe directly then it works fine but with dynamic binding it shows the below error:

The url that I’m passing is of ionic official web app. It shows the same error for all the urls.

@rapropos @Sujan12 Need your help here