The reaction you are describing is not reasonable and large, reputable websites just use Anubis.

Either you are a creep or otherwise come off as creepy due to Audhd things or unwashedness and hence ellicit this reaction or you have a very weird work culture with people being far removed from tech. I presume it is the latter. Hence giving a simple recommendation with condensed information is much more appropriate than just dropping a link and posing a significant challenge to the people in charge. Being scared of being perceived as creepy may also cause you to be perceived as creepy. A potentially great way to phrase it is stating: “look, here is a great, free and secure tool to do this. They come with a weird anime mascot to encourage commercial customers to pay for their software while being free for private and open source users. It’s just 50 Bucks to remove this so we can just do that. If we don’t feel like paying for this we also could just use Anubis directly, but I feel like we should go with their commercial offering.”