Migrating Photos from Envira to Modula

Hello,

We have a personal web site we put together for our travels OS and I ma trying to update things a bit and have been advised to update to Modula Plug In from Envira.
Within the Modual plug in I can use the Migrate button but it only found one Gallery source of a limited number of photos.

How do i go about migrating the remaining photos over (approx 400 photos) I dont have the original folder of photos on the computer so need to use the existing ones in Envira

Any help would be appreciated

David