Form 8829  is for Schedule C only.   See instructions for Form 8829, page 1, bottom of first column.....

Who cannot use Form 8829. Do not use Form 8829 in the following situations.
• You are claiming expenses for business use of your home as a partner or you are claiming these expenses on Schedule F (Form 1040 or 1040-SR). Instead, complete the Worksheet To Figure the Deduction for Business Use of Your Home in Pub. 587. (You cannot claim expenses for business use of your home as an employee.)

So IRS Pub 587 has the information you need for deducting the home office as a partner.