[Sell fiverr services on through my blog?]

Can I sell my Fiverr services through my blog?  - That I know of, yes.
May I post the Fiverr gig link in the content? - I guess yes? the "share your completed gig on social media" always appears after you complete a gig.

Is there any other way to sell Fiverr services? - Use the "bring your own client" (search Fiverr about it), earn commissions through other Fiverr services Fiverr offers (like promoting banners and new services. Don't you get the Fiverr newsletter? -They even tell you how to level up your career through Fiverr Training)

Kind regards.