I can't believe I have to even say this, but for all you looking for work…
If there is no Salary stated, then don't interview. In fact, don't apply EVER. Don't message them, don't call them, don't email them asking.
There are no circumstances where this is ever going to pan out in your favour.
Employers do this for one of two reasons:
1) The pay is so low that people don't apply, they need people on the hook do they can convince (gaslight) some mug into accepting pittance as that's all they are going to get.
2) They want to negotiate I e. screw you as low as they can. Even if they have a budget of €150k, they need a info from you as to how low they can screw, so you even mention $50k, they will use that to push you lower, they will test your boundaries.
So some of you will be thinking, “yeah, but I'm special, I'm a really good negotiator, by the time I'm finished with them they'll be paying $100k for a customer service role, + benefits”.
You're an idiot, they won't. Even if you have some “cerulean blue” convincing skills with the interviewer, HR will kick it out.
So just don't ever even apply for a job where they haven't given a reasonable salary in the advert.