Is it possible to detach Laravel from a hosted domain via Laravel Toolkit in Plesk?

As a workaround, you can remove the application manually with the steps below:

 1. Remove the website's files from Domains > example.com > Dashboard > Files

 2. Remove the git repository that was added during the Laravel installation from Domains > example.com > Dashboard > Git 
 3. Create a backup of the Laravel extension database just in case with the command:

# cp /usr/local/psa/var/modules/laravel/laravel_toolkit.sqlite3{,.bak}

 4. Access the database with the command:

# sqlite3 /usr/local/psa/var/modules/laravel/laravel_toolkit.sqlite

  5. Check the ID and/or name of the laravel instance you want to remove by checking the application table. For example:

CONFIG_TEXT: sqlite> .headers on
sqlite> select * from applications;
id|domainId|name|repoName|deploymentPath|scheduleTaskId|repositoryType|scan
...
3|2|example.com|laravel_945d29|httpdocs/public||local|0

Note: In this example, we want to remove example.com with ID number 3

 6. Remove the instance from the database by running the query:

CONFIG_TEXT: sqlite> delete from applications where id=3;

Or you can also use the domain name like:

CONFIG_TEXT: sqlite> delete from applications where name="example.com";

Make sure you use a primary key so you don't remove other instance by mistake.