Yes! If you want to add schema to a 
specific post only (not the whole WordPress site), you can do it manually or with a plugin.
 Manual Method
 Manual Method:
Use a plugin like 
Code Snippets or insert custom schema markup (in JSON-LD format) directly into the <head> of that particular post using a plugin like 
Insert Headers and Footers or by editing the theme’s single.php file 
with conditional tags to target the post ID.
 Plugin Method
 Plugin Method:
Tools like 
Rank Math or 
Schema Pro let you add custom schema to individual posts. In Rank Math, just scroll down in the post editor and use the “Schema” tab to choose or create a schema for that post.
Just make sure to test your markup using Google’s Rich Results Test after adding it.
Hope that helps!
Tools