This package depends on chromium-embedded-framework, for which I filed a separate RFS yesterday (#1124290). CEF resolves ITP #915400, open since December 2018.
Both packages: - Target experimental (CEF requires chromium sources not yet in Debian) - Have been tested together - Are available for early testing at https://debian.vejeta.com/
I recommend reviewing both packages together, as stremio-gtk demonstrates that CEF works correctly in a real-world application.
Background: My previous stremio package (Qt5-based) was rejected because Qt5 is EOL. This GTK4 version is the modern replacement.