I made a new badge but I don't know how to apply it to users. I have it set so that it says can be manually applied. I just can't find how to apply it and where.

Thanks.

On a post that you want to reward someone for, you will click the three dots on the post "Reward {user}" and then make the badge selection you want to reward them with:

When I click the 3 dots this is what I see:

Also does this reward stay with just this post or on everything they do?

I might be going about this the wrong way. This is a Site Supporter, made a donation and I want to give them a custom badge to show my appreciation.

Thanks.

A reward is shown on the post, but given to the user as a whole. If you want it not to show on the post, and only show on the users profile, you would do this in the admin CP from their profile instead.

If you are not seeing "Reward user" than its because you dont have the permission set for yourself or your group in Members->Staff->Moderators, under the content tab