HEre is my checkout url

https://exportlangjson.lemonsqueezy.com/buy/cdc352cc-c8ef-4137-8283-a26ac9e506b4?embed=1&media=0&discount=0?checkout[custom][user]=%7B%22id%22:%(I delete id type is number)%22,%22photoUrl%22:%22https://s3-alpha.figma.com/static/user_h_v2.png%22,%22name%22:%22Huseyin%20AKKAYA%22,%22color%22:%22#9747FF%22,%22sessionId%22:387%7D&checkout[name]=Huseyin%20AKKAYA

When I open I get 422 error

I fill the form but Start trial button does not give any action
Can someone help me ?

I use before without any error and suddenly I get that error