Answer:
To generate surface imperfections based on the governing buckling mode, you need the "Structure Stability" add-on. Activate this in the general data of the model in the "Add-ons" tab; see Image 01.
Then, perform the structural stability for the corresponding load case (or load combination) by activating it in the corresponding load case and selecting the corresponding stability analysis setting; see Image 02.
After the mode shape has been calculated, define an imperfection case with the "Buckling Shape" imperfection type, including the corresponding parameters in the respective tabs "Basic", "Buckling Mode", and "Assignment"; see Image 03.
Now, create a new load combination according to the second-order analysis (default setting) and activate the corresponding imperfection; see Image 04.
When calculating this load combination, the corresponding imperfection is taken into account.