Here is the actual claim - https://www.documentcloud.org/documents/24408674-shad-white-counterclaim-against-brett-favre - in relation to the principal and interest owed here - pages 28 and 29 calculate this
December 27, 2017: $500,000 funneled to Favre
June 2018: $600,000 funneled to Favre
$1,100,000 total sans interest
By May 5th, 2020, Favre owed $1,100,000 in principal and $437,000 in accrued statutory interest ($1,537,000 total)
May 6, 202: Favre admits he is personally responsible and will pay back the state the full sum of plus interest he owes "in the coming months"
May 7, 2020: Favre pays $500,000. This leaves a balance of $740,000 in unpaid principal which continues to bear interest plus $132,000 in already accrued interest
October 25, 2021 (over a year later - lots of accruing interest): Favre pays $600,000 which reduced the principal owed by Favre to $437,000 with no further interest at that time
February 5, 2023: Favre still owes $437,000. Since October 25th 2021, another $292,790 in statutory interest has accrued from the $437,000 he still owes.
$437,000 + $292,790 = the money in the claim (which will continue to grow with interest)
Explained in the linked filing