Hi,
Sorry for the trouble. Fixing the undefined array key error in WordPress can be a tricky task. Fortunately, there are a few steps you can take to identify and resolve the issue.
First, you should try temporarily switching to a default WordPress theme (such as Twenty Twenty) to see if the error persists. If the error does not occur when using a default theme, then the problem is likely with the custom theme that you were previously using. In this case, you will need to contact the theme developer for assistance or consider switching to a different theme.
If the error persists even when using a default theme, then the problem is likely with a plugin. In this case, you can try deactivating all of your plugins to see if the error goes away. If the error goes away when all plugins are deactivated, you can then try reactivating your plugins one at a time until you find the one that is causing the problem. Once you have identified the problematic plugin, you can try reaching out to the plugin developer for assistance or consider finding an alternative plugin.
Finally, it’s important to make sure that you are using the latest version of WordPress and all of your themes and plugins. Outdated software can often be the cause of errors like this, so updating to the latest version may help resolve the issue.
If you need any further assistance, please don’t hesitate to reach out. Good luck!