Warning: Undefined array key “number”

Hello @bdthemes,

Thank you for contacting the support and sorry for any inconvenience that might have been caused due to that.

It seems like you left the number field blank in the Local SEO settings:
https://i.rankmath.com/nNS8Yf

We have here a condition here that checks the first entry.
https://github.com/rankmath/seo-by-rank-math/blob/master/includes/modules/local-seo/class-local-seo.php#L231

We check only the first entry because that’s the default field that we add when the plugin is installed. We can improve this code by adding a condition to check all the phone numbers entires. We have reported it internally to improve it.

For now, you can remove the blank number fields from Local SEO settings.

Hope that helps.