Two jobs, 403 b and sep Ira

If myW2 job has a 403b and my employee and employer contributions are $58,000 (max) for 2021 can I still contribute to a Sep-IRA for 2021 if  I have a side gig consulting solo employee job too (1099 payments)?  I keep getting different answers from different accountants since 403 b is different under IRS tax code than a 401 K.  Today I was told I could contribute to a Sep-IRA.