Download Solidworks 2021 with Serial Number

Hello All, 

I had an old computer, Computer A, that had Solidworks 2021 on it. I released the license but when I go to mysolidworks I cannot choose to enter that serial number and get the download for a new computer, Computer B. 

 

I cannot find anywhere to ask support either. 

 

How can I get the download so I can move it from the other computer?downloads2021SolidWorks