Yep this is the process.
https://www.howtogeek.com/876077/how-to-delete-facebook-notifications/
Nothing is intuitive anymore so I always have to Google my question, find a how-to page and follow the steps. I still like FB for interaction with lifelong friends but I am not interested in chatting with some Chinese catfish scammer who wants to be my friend. I do also use FB marketplace to good effect but screen and block nuisance interactions quickly. Scammers always have a tell.