Deno add from different sources (like JSR) doesn't works?

Hi, I'm new with Deno.
The problem is:
I copy-paste this code

deno add jsr:@oak/oak jsr:@tajpouria/cors

deno add jsr:@oak/oak jsr:@tajpouria/cors

and deno search it from npm and not jsr, it gives me the error

error: npm package '@jsr/oak__oak' does not exist.

error: npm package '@jsr/oak__oak' does not exist.

why?

Deno add from different sources (like JSR) doesn't works? - Deno