If it was easy to automate, then spammers, scammers and corporate pigfuckers would completely inundate marketplace with so much garbage it would be utterly unusable. Accept that the only reason your 1 Facebook ad per day produces any results at all is because it’s hard to automate, and if it weren’t, nobody would ever see any of your ads. The fact that you’re hunting for IDs instead of page structure patterns already suggests a novice level, so imagine all you needed was awareness that Selenium exists in order to spam Marketplace to death with MLM ads and scam posts. There are already way too many scam posts when a person actually has to interact with the site. If you could easily do what you want, you wouldn’t be able to sell anything, because >99% of content would be bot posts without aggressive content moderation. That moderation would either be human, which is expensive, or automated, which would be very inaccurate and take down more legitimate posts. There’s no world where you can legitimately automate this and bad actors can’t.

If I had an answer that would help you, I would never post it because it would actively degrade everyone’s Marketplace experience, including yours, until FB fixed it and made it hard to automate again.