Type in schedule J in the search box, use "Jump to schedule J", farm income averaging.
Here is some reference material you may find useful when filling out schedule J.
https://turbotax.intuit.com/tax-tools/tax-tips/IRS-Tax-Forms/What-is-Schedule-J--Income-Averaging-fo...
https://www.irs.gov/pub/irs-pdf/i1040sj.pdf
