This code enables you to use the
single_template filter in a custom function from your plugins functions file to change the template used in your parent or child theme.
Single Custom Post Type Template
This PHP code enables you to load a template for your custom post type from a plugin.
Single Post Type Template
This code enables you to load a template for your all single posts from a plugin.
Both snippets assume your template is located in your plugins root directory and the code has been added to your plugins functions.php file.
There are various other methods you can use to load templates from your plugins folder.