@Gus
Make sure you have the most recent edition of the Instructions for Form 1040 and 1040-SR. The revision date at the bottom of the cover page is April 13, 2021. Download it from this link.
Instructions for Form 1040 and 1040-SR
Go to page 31, Social Security Benefits Worksheet. Line 6 of the worksheet says "Enter the total of the amounts from Form 1040 or 1040-SR, line 10b, Schedule 1, lines 10 through 19, plus any write-in adjustments you entered on the dotted line next to Schedule 1, line 22."
