The best alternatives to MonetizeJS are Hashnode, Unlock, and PayRequest. If these 3 options don't work for you, we've listed a few more alternatives below.
Kale helps nanoinfluencers (<10k followers) make a passive income. We give them offers from the brands they have purchased at and let them decide whether they want to post or not so they stay honest to their audience, no strings attached
Create shareable, trackable payment links on the Solana blockchain. Anyway, we are in the early stages of what is to come - blockchain native API features.