Form 843

I worked for the same umbrella organization for 2021, but changed from one affiliate to another one mid-year.  The umbrella organization withheld social security for each affiliate and sent me a letter indicating that they would not reimburse me for the excess social security withholding and that I would need to file Form 843 with my return.  My questions are the following:

1. Can I file this form through TurboTax?

2. If not, I've found the link to this form on the IRS website along with instructions, but I don't know if I should E-E-file through TurboTax and then mail in the separate 843 form or if I should file both by mail?

 

Thank you for any help/recommendations!