Request Type: GET
Enter the request URL: http://StoreURL/odata/picture
Auth type: Bearer Token - paste the token generated in the previous steps
Request Type: GET
Enter the request URL: http://StoreURL/odata/picture('id')
Auth type: Bearer Token - paste the token generated in the previous steps
As a result, you will get your picture.
Request Type: POST
Enter the request URL: http://StoreURL/odata/picture
Auth type: Bearer Token - paste the token generated in the previous steps
Headers: In the Key field enter the Content-Type, in Value field enter the application/json, description is empty.
Body: In the body field you need to enter the proper JSON. Which fields are necessary for specified actions you can check in the bottom of $metadata page, section with EntityAction. This method requires more actions from you.
You need to know the MIME Type, list of MIME types can be found here: https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Complete_list_of_MIME_types
If you want to insert picture, you need to have BASE64 code of image. You can convert your picture here: https://www.base64-image.de/
Request Type: DELETE
Enter the request URL: http://StoreURL/odata/picture('id')
Auth type: Bearer Token - paste the token generated in the previous steps
Please note that in DELETE operations, you will get only "Status: 200 OK" information if the item was successfully deleted.