For a library like this, the only really appealing pricing model is a flat fee that buys unlimited use of the version I buy in perpetuity (even if that fee is several thousand dollars). I'm not, however, going to pay monthly forever for code that (1) you wrote once and is now static, (2) that you aren't hosting, and (3) that I need to integrate into my application myself. That feels like paying my car manufacturer a monthly subscription for heated seats [4].
If I need support I will happily pay you a support fee. Moreover, I cannot take on the liability of my app's bar code scanner ceasing working because you decide to close your doors and then the license won't reactivate.
[1]: https://github.com/mebjas/html5-qrcode
[2]: https://strich.io/comparison-with-oss.html
[3]: https://blog.minhazav.dev/research/html5-qrcode
[4]: https://www.theverge.com/2022/7/12/23204950/bmw-subscription...