After getting this amazing answer explaining the procedure of how to create secure end-to-end encryption here

Some of the steps were saying that you have to generate a certificate signing request (CSR), and send it to the CA, and also validate it with the CA.

After a lot of researching I can't find any useful information about if this can be done in the web browser API with JavaScript. I found a few libraries that does it in NodeJS such as pem and forge, but I must do these steps within the client, which is the whole point.

Are browsers lacking this support?