From Spaceman Effects:
"Mission Control is: an Autofader, Signal Router, Dynamic Effects Loop, Wet/Dry Blender, Y-splitter, Two-channel Mixer, Customizable Tremolo, Buffer, Interface for CV and Expression Control, and more."
You have copied the placement for the Product Page.
Go back to the App Embeds section, and in the Paypal Advanced Settings, paste the copied value into the Product Page field and click the 'Save' button in the top right corner.
