Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Greetings!
This is Tin, may I know what is the error message that you're getting? Have you tried to use other browser and check if the issue persists? Or how about clearing cache and cookies? To do that, please press CTRL +SHIFT +DEL then choose the Cache also Cookies, then hit Clear Now. Then please try again. You may also check if its already associated on your account, go to https://account.microsoft.com/services if it's already there it means it was successfully redeemed, you can install it from there.
If the issue persists, please try to use other device. And if it's still the same, kindly reach MS Accounts & Billing to check this:
Kindly open this link: https://support.microsoft.com/contactus/
Ensure that your MS Account has been signed in
Type "Chat with an agent" and hit Enter.
Please click the "Contact support"
Please select the "Products and services"
Please follow the prompts to connect with a live agent.
You may also choose the "Call me back" option if you prefer to receive a call.
Once you're connected to the Live Agent, please let them know about your issue so they could check your account and address your concern.
Thank you,
Christine