That is amazing.
A allows a larger donation. SEP IRA - A Simplified Employee Pension IRA is designed for small business owners with several employees and self-employed individuals. If you are eligible for a SEP IRA, you'll be able to set aside up to either 25% of your compensation or $58,000 in 2021, whichever is less.
There are rollovers allow, also, but I would think there must still be some backdoor method of contribution.