iBGP question on Peplink Device

We have an ASN number and a x.x.224.0/21 IP block. We splitted into two x.x.224.0/22 and did BGP perring with a provider. Now we have another provide and also just did peering with them on the remaining x.x.228.0/22 block as show in the diagram. Now we want to get a peplink BPL-2500 to see if we can use drop in mode (layer 2) to do an iBGP between the two links at our ends and use the IP x.x.228.0/22 on our LAN as also shown in the diagram.

Is this possible, if yes, we have two peplink device mediafast 750 and BPL-380 sowe can test and if everything is fine we can order the BPL-2500.

Please can someone help us on how to achieve this config? our netowking knowledge is low to mid. Thank you