I have two azure subscriptions and I have a formula in one of them who is inside a Azure DevTest Labs I have searched for it on the documentation but I couldn't find anything what I found was scripts to copy VMs, however, that is not what I need because in that way the VM has to be already created and what I want it's copy the formula I have in subscription 1 to subscription 2
You can programatically create formulas using ARM templates. A sample template for creating a DevTest formula is here. I don't have a DevTest lab created but most resources in the Azure Portal have an "Automation Script" blade that will show the current ARM structure, you can pull your existing formula from there.