Hello,
Thank you for contacting Rank Math support today and we appreciate your interest in trying out our new Content AI feature.
Free users are given 5 free Content AI credits so you could test it.
Can you please head over to your rankmath.com Account > Website or visit this URL: https://rankmath.com/my-account/websites/?
Check if you are able to see the correct remaining credits. See my screenshot below for reference:

If the credits are correct, then, please head over to your Content AI and refresh the credits count so the plugin will request the updated credits from our server and displays the correct one.
If that doesn’t work, please head over to your WordPress Dashboard > Rank Math > Dashboard > Help, disconnect your account there and reconnect it.
As for the AI credits, the credits you have received are one-time use and will never renew or refresh. We are actually planning on rolling out an AI credit purchase system so you can purchase credits separately. Rest assured we will let you know once we have introduced it to the users.
Looking forward to helping you on this one.
Hello,
Since we did not hear back from you for 15 days, we are assuming that you found the solution. We are closing this support ticket.
If you still need assistance or any other help, please feel free to open a new support ticket, and we will be more than happy to assist.
Thank you.