Fix Incorrect hreflang implementation on sitemap and in website

I need a sitemap expert to review the current sitemap and identify any needed website change as well. Google has detected that some pages on your site have implemented the rel-alternate-hreflang tag incorrectly. In particular, there seems to be a problem with incorrect language and region codes, or incorrect bi-directional linking (if page A links with hreflang to page B, there must be a link back from B to A as well).