there is no such line for 2019 on fed 1040 are you in 2018 fed return or a state return.
2018 line 71 fed 1040 schedule 5 was for extension payment.
If you didn't notice the form 1040 changed in 2018 and again in 2019 to include several schedules ...
In 2018 line 71 is on the Sch 5 line 72 .... and in 2019 the excess SS is on sch 3 line 11.