Stellaris force_integrate command

This command integrates <span class="parameter parameter-primary">Country ID</span> empire into the player's empire.
Command syntax
force_integrate <span class="parameter parameter-primary">Country ID</span>
Example
force_integrate 5
How to open the console in Stellaris
Press the ~ / ` key to open the command console. This key is located at the top left of the keyboard, usually under the F1 or ESC key. Type the command and press the Enter key.