fix: types

[florian-lefebvre]

According to https://stackoverflow.com/questions/61047551/typescript-union-of-string-and-string-literals, the right type to allow any string is not the one I initially suggested. It works but since there's a better way, here is a quick PR for it! cc @rishi-raj-jain

[rishi-raj-jain]

Thank you for taking the time and energy to make the PRs 🤍