如何使用base64编码的url使用PHP嵌入iframe

I have seen a lot of tutorials which explain how they can encode images into base64 and can be embedded but I am trying to embed a simple URL to be encoded in base64. like this below

<iframe src="https://somelink.com" width="640" height="480"></iframe>

I am trying to encode https://somelink.com into base64 which may somewhat look like this aHR0cHM6Ly9zb21lbGluay5jb20= can I embed this under iframe in src field and hide URL from being shown in view-source.