I’m having trouble with Related Product “tax_query” ‘terms’ value

I have two custom page types. the first is “product” and the second is “accessories”. On the product page, there is the accessories category “inputs” raleted post. Inputs encode values like “0601,0603 etc”. These codes are also product codes. When I enter the product code with the metabox, functions start in certain areas. such as product table, product picture. How can I print this code in the term section.

how to load random related posts with specific custom fields?

I want to load 3 posts that have the same custom field value as the current post.
for example:
The current post has 3 custom fields:
color: black
background: red
lastname: doe
Now I want to load three posts with these custom fields:
first post: color:black
second post: background:red
third post: lastname:doe
these are my codes:

Recent posts on homepage: different thumbnail based on logged in status and post category

This works well on archive.php, but not working on the homepage. For some reason, the first statement doesn’t get applied: if a post is in Members category and user is not logged in, it’s supposed to show a default placeholder image, but instead it’s still showing the actual post thumbnail.