Check your amended 2020 tax return to see if there was balance due, which is shown on Line 20, Form 1040-X. If you did not send in a payment, and there is an amount on that line, then you should send a payment now. If you have a refund on the amended return then you can ignore any the ES form. This appears to be an estimated tax form, however I can't be sure (1040-ES?).
Use this link to find a mailing address if necessary: Where to send IRS balance due payments
If you actually do have a refund, the IRS will send the money once the amended return is fully processed.