MPWP and new USB SSD

I need portable large double backup solutions.
I want buy 4TB MPWP and 4x WDBKVX0010PSL-WESN for double backup.
Would this drives are connected to MPWP and can I transfer files from SD(or intrel hdd witch more worst) to this external USB SSD?

You can transfer the files from SD Card to the My Passport Wireless Pro only as it features the SD Card backup directly from the Card to the My Passport Wireless Pro.

Whereas, My Passport SSD is plug-n-play drive which you can use with your computer. You need to connect the SD Card with your computer as well as the My Passport SSD in order to transfer the data of SD Card to the My Passport SSD Via Computer.

I can’t get computer to this trip.
Can somehow transfer files from SD to external hard drive via mobile app?

No, but if MPWP is up to date with all your SD card transfers you can connect wireless drive via USB and SSD drive to same computer to do transfer of filess

I can’t get computer, can I transfer files form MPWP to external disk via mobile app?

Once again,no. Even if you could, it would take “forever” via wireless internet. MC mobile app is only for downloads or streaming your media files.

Did MPWP has same web interface like my ex2? Ex2 have app “web file viewer” and I can with phone star copying files to external disk

Not at all the same GUI. Install My Cloud app on phone or tablet and see for yourself.