Add rewrite rule for Update AMP Content

Question

I want to update AMP Content from admin.

I am following steps which is given in following url:

https://developers.google.com/amp/cache/update-cache

As in step

For signature verification, you must serve the public RSA key at a fixed location on the AMP document's domain

I am accessing https://example.com/.well-known/amphtml/apikey.pub

by add_rewrite_rule( '.well-known/amphtml/apikey.pub?$', 'index.php?pagename=amp-pub-key', 'top' ); By this rewrite rule i am unable to do this.

Please help