Because you are not a qualified "eligible designated" beneficiary, you must distribute the full amount within 10 years (by 2031).
You are also required to take RMDs during the 10 year period. This rule is not written in the current (2022) version of publication 590-B because the rule was not finalized for the 2022 tax season, but a final rule is coming. (The IRS will not penalize you if you failed to take an RMD in 2021 or 2022, because the rule was not final at the time.)
So you should plan to take an RMD (or more) this year and in the future. The RMD is calculated according to a different formula that @dmertz knows but I don't.
You may want to take more than the minimum so you can spread out the taxes. If you only take the minimum you will have to withdraw a big lump sum in the 10th year and that may have negative tax consequences.
