Potty Training Pull Ups for children who are potty training come in 3 sizes which are sizes 2T–3T (18-34 lbs.), 3T–4T (32-40 lbs.) and 4T–5T (38+ lbs.)
If you need larger size pull ups you'd have to buy youth size Pull Ups for older kids or if you need adult sized pull ups you can buy adult sized pull ups as well.
But in toddler sizes the Pull Ups only go up to size 5 T which fits a toddler of around 38 lbs and sometimes 40 lbs.
The largest size I used on my kids who were fully potty trained by age 3 years and 6 months is the size 4 T to 5 T.
If I needed larger size Pull Ups I would have had to buy youth Pull Ups.
You can also buy cloth training pants which is what I wore as a kid when potty training but the disposable Pull Ups are much better as you can just throw them in the trash and not have to worry about washing them.