Ed Pawlowski wrote:
by, enough to cause a slow down.

Are other toilets and sink draining properly?

Fill a bucket with water. Flush the toilet. As soon as the bowl
empties, pour in enough for another flush, then maybe another. That
will either back it up so you can judge the distance, or purge the
solids in the line if it is a hang up of paper or a tampon, etc.

Or mess up the basement.