Best way to improve intonation?

I’d say my pronunciation in Japanese is quite decent. I’m a native speaker of Slovak, which has relatively similar sounds to Japanese, so my accent is pretty good. However, the one thing I struggle with is intonation. I’m from central Slovakia and even other Slovaks say we “sing” when we speak because our intonation goes up and down a lot in sentences. However, I have recently found out that I also need to work on my word-level intonation and stress. I tend to put the stress on the first syllable (L1 influence) and I know it’s not right in Japanese. Is there an app or something (I’m happy to pay) where I can practice by shadowing or repeating sentences (not necessarily at the same time) that specifically focuses on proper intonation/stress? I’d love it to focus on differences between words like 花 and 鼻, 読んだ and 呼んだ, etc., you get the idea. I’m level N1 btw. Thanks! Btw., I already listen to audiobooks a lot, but that alone doesn’t help much.