Filing Status - 2020 Return

I had to file my return this year by mail this year because multiple efiling attempts were rejected.  I filed the return in the second week of April 2021.    I haven't been able to find out if the return was even accepted by the IRS (I do have a USPS receipt that it was received).  I attempted to use the various IRS tools to find out my return's status but cannot find any information.  Any thoughts on where to turn?