License Key Not Accepted by Premium plugin

When I enter my license key from the generatepress.com dashboard to enable the Premium version

Do you mean the dashboard of Appearance > Generatepress?

If so, do you see any specific error code?

Can you check if your case matches any of these ones?
https://docs.generatepress.com/article/403-forbidden-when-activating-license-key/
https://docs.generatepress.com/article/updating-issues/

Let me know!

Yes, exactly, it's at Appearance/GeneratePress.

I've included a screenshot showing the behavior. The icon spins but nothing happens. There is no 403 error or other error message.

Who are you hosting with?

I'm with Scala Hosting, on their Dallas servers. I have multiple sites running GP Premium using the same hosting account, and have had other hosts in the years I've been using GP, never seen this issue before. BTW, I've since rebooted and cleared my browser cache — no change.

Hi there,

any CDN or server side caching enabled on that site ?

Can you also try the secondary API method here:

https://docs.generatepress.com/article/403-forbidden-when-activating-license-key/#secondary-api

No CDN or server-side caching that I'm aware of, but the secondary API method fixed the problem. Wondering why this would be necessary? The only thing I can think of is that the server is running Open LightSpeed. Possible issue there?

Also, do I need to keep the secondary API script in place to receive updates?

A couple of users had the same issue when Litespeed Cache is enabled.
Unless you can find the server setting thats blocking the request, then you need to keep the Secondary API script in place.