You absolutely should use the rebar circles as specified in your repairs as they greatly lengthen the life of the repair.

Part#: P-MM0316

Product Link: https://mrmanhole.com/product/re-bar-rings-40-in-a-bundle/

Resource: https://www.youtube.com/watch?v=rcGaOI5QyfY

Additional Resources: https://mrmanhole.com/rebuild-method-for-manhole-repair/