The version distributed on Play Store makes use of dynamic feature modules, i.e. the code needed for this feature is downloaded on demand.
This solution is not available on the versions distributed on F-Droid, Amazon AppStore and Huawei AppStore. Therefore text recognition capability is provided by an OCR helper application. This helper is available in two variants, one based on Ml Kit (proprietary), the other based on Tesseract (OpenSource). The Tesseract variant can be installed from F-Droid(https://f-droid.org/packages/org.totschnig.ocr.tesseract/), the Ml-Kit variant can be found on the project's release page on Github.
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