I wonder if I could monetize my site on free plan or on an other plan.
Yes! Feel free to monetize your website!
google adsense does not work with webhostapp for example
What error are you getting?
You can’t use google adsense with a subdomain. Please consider buying a domain from hostinger.
Then you can add your domain to adsense.
I have posted an adsense ad code but it doesn’t appear enything
Did you buy a domain first?
no I have free domain