In the free BIMx App you can purchase the BIMx PRO functionality with the “BIMx PRO license” option. This license can be used on four other devices (having the same Apple ID) by restoring the purchase. If the App was deleted from the device accidentally the previously purchased license can also be restored in BIMx the same way.
To restore your purchase follow these steps:
Three options appear, scroll down to the last one and choose the “Restore Purchase” option.
Sign in with the Apple ID you used for the original purchase. After this your purchase will be restored.