custom function from a bedrock wp theme, into a standart wp project

i have a custom function (from old bedrock theme) of creating 2 new menus in wp-admin (daily news and monthly news), the posts that are in those menus are collected from a remote server via API token, the posts themselfs exist, they are scheduled. I can open any of them and see the title and date, the thing is that there is no content or images. (on the new theme)

i have tried to install the old theme from bedrock in which was this custom function, it did work perfectly, but i cannot use the old theme, so i don’t know what to do.