How to adjust W-4s for married filing jointly, 2 full time jobs and a side gig

My husband and I both have full time jobs with W-4s for each (my full time job brings in more income than his). I also have a side gig with a third W-4 (this brings in an extra ~30k a year, but is the lowest income out of the three jobs). We have filed jointly for the past couple of years and have owed a lot on our taxes since the addition of my side gig, but have not updated anything on our W-4s since filing separately. We are pretty stumped on where to start.