By default, as a requester, standard spots (for cars) are allocated to you. If you do not use a car and wish for the platform to allocate you another type of spot, you can change this in your account.
Click on My account in the navigation bar at the top of the page.
Select the type of space requested by default, here it is standard type :
Then select in the list the type of space you need to request by default :
Small spot may receive a standard spot or a large one. Big spot requester can't receive a standard or small spot.