No, you can’t. This is due to the difficulty in supporting and adapting the .proto.gz or .tachibk format that Tachiyomi uses. Also Kotatsu and Tachiyomi and its forks have different data structures that they use. For Neko for MangaDex users we recommend to use Nekotatsu.
Wonder if they will figure out a way to import Tachiyomi backups or series lists now…
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https://kotatsu.app/manuals/faq/general/#can-i-restore-my-tachiyomi