However, what DanaB27 describes is not a "recharacterization." A recharacterization would make the contribution be a traditional IRA contribution for 2020 rather than removing the excess Roth IRA contribution and leaving you with no contribution for 2020.
You also have the option to leave the Roth IRA contribution for 2020 as is, pay the 6% excess-contribution penalty for 2020, then apply the excess as your 2021 contribution. You would consider doing this if the investments in this Roth IRA appreciated appreciably, say, something like 30% or more, after you made the excess contribution. This would allow the nontaxable gains to remain in the Roth IRA and eventually more than make up for the 6% penalty. If you consider doing this, just be sure that you will be able to apply the excess as a 2021 Roth IRA contribution so that you do not incur additional penalties on this excess.
