Backed up application has been saved in 3 parts

[Zygus]

Hello. I have backed up application with TC and as the final result I got 3 apk files.
The application was Tapas (offical comic reader) and beside main apk I got
Tapas 6.5.12-split_config.armeabi_v7a.apk
Tapas 6.5.12-split_config.hdpi.apk

Do I need all these three apks to restore app or I only need the main apk?
Trying to reinstall apk from 2 split apk will give an error of course.

[ghisler(Author)]

Yes, this is the new app bundle Google tries to push: It splits an app into multiple parts, by
- native code by processor type (here: ARM 32-bit)
- images by screen resolution (here: high dpi)
- languages (if there are translations)
- and of course the main apk with the Java program code.

Yes, you need all parts.

[Zygus]

Thank You.
So until I don't rename the additional files and put all of them into the same location there shouldn't be any issue
reinstalling the app.
Is there possibility that the other file managers can have issues with installing such multiparted app?
Those three files I got from one device, and then put them into Huawei P20 Lite. Due to issue with apk support in TC i tried to install Tapas in Huawei file manager but it always failed. But with sideloaded TC 3.33 the Tapas app installed without worries.

[ghisler(Author)]

Indeed the normal Android apk installer can't install split apk files. There are some site-specific formats for split apk files like apks, xapk etc. which can be installed by the installers of these sites. Total Commander can also install these. They are usually a ZIP file with split apk parts inside, plus an icon and some kind of descriptive text or xml file.