I can't agree to terms and conditions when installing the OS

I managed to get an OS on the new SSD and boot from it. After failing in the Disc Utility recovery mode of restoring the blank (and erased) SSD from my original HD (from another identical mini with a failed power supply) I tried copying the HD in Finder. The new SSD showed up as a valid startup disc choice but it would not boot. This time with what appeared to be a corrupt OS (instead of being blank) I was able to use Disc Utility to recover from the first HD. I'm using the new SSD as I type this.

The only difference I can see in the two recovery modes is the first time I was booted on the first HD (mounted externally) and the successful time I was booted in recovery mode using that Disc Utility. But I never got an error that Disc Utility could not recover form a HD that the computer was booted from.

I contacted the seller. They were the owner and removed the mini from their account. They verified that it is no longer on their account. What if I boot from an external HD? I've been using the HD from a mini that lost a hard drive on another identical mini. Would booting it on a working OS write my ID on the motherboard and register it with my Apple account?

The seller did a fresh install of Catalina and removed it from their Apple profile. I could not agree to terms. I booted with Option-CMD-R and Apple gave me Mavericks, the original OS. I could not agree to terms. It will be a few days before I have time to try anything else.

I have scrolled up, down left, right, and inside out looking for something to click. I opened all the terms and scrolled from top to bottom. There is nothing else to click. I've hit the Enter key. I've hit the Return key. I've clicked on Agree 100 times. I've gone back and re-entered my login 10 times. I'm using a wired USB keyboard and mouse

Nothing.

Well, I was able to download an OS from Apple. When I booted on the seller's install it started with the normal entrance screen to select language and progressed to registration where I entered my Apple ID and it was accepted. When I could not agree I then tried the method where you download the OS and install it and went through the same process. Both times the Agree button was gray and not clickable.

The mini had a fresh install of Catalina when I bought it. I could not agree to terms. By booting in Recovery I downloaded and installed Mavericks, the next OS after the original OS and could not agree to terms. I have booted the mini from an external HD (from mine with a dead power supply) successfully and verified that the new mini's serial number is on My Apple profile. I have tried a rescue to the newly installed SSD from my externally mounted old HD but it fails because the new SSD can't be unmounted (that's the error in Disc Utility). I have scrolled up, down, left, right, hit enter, hit return, hit escape, and nothing lets me click on Agree.