You can convert placeholder pipe to pipe with fittings.
The type properties of the placeholder elements determine the fittings to add. For example, if a pipe placeholder is created with a type of PVC pipe with taps, then the placeholder elements will be converted to PVC pipe with taps instead of with tees.
Edit panel
Convert Placeholder. The placeholder pipe is converted to pipe with fittings.
Show Related Warnings available on the ribbon, you can click it to review warning messages related to converting placeholder pipe layouts.