You can use freefile software

1.  The foreign pension is reported on

Schedule 1, 8 Other income. List type and amount, You type in "Foreign pension" $xx,xxx

Then transfer schedule 1 to 1040-SR, line 8.

2. You can use freefile program from IRS, https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free

Various tax reporting softwares participate in the program.  I used Turbo Tax for my parents, it is free for federal income tax but not free for state tax returns, if applicable.