If you want to add a Store pickup option to your Magento2 Marketplace then you can use the Magento2 Store Pickup Marketplace Add-On.
This add-on allows sellers to add their store to their marketplace profile. Using this add-on, sellers can different physical stores along with the store address, zip code, store contact number, store opening timings, etc.
Please do contact us for any further queries or requirements. You can also check our Magento 2 Extensions for additional features.