Form builder in Kirby v5 (or, if necessary, v4)

I did a little research and found

Does anyone in the forum have any experience that could help me choose the right plugin?

One essential criterion is that editors at a conference organiser who are familiar with the basics of HTML forms can add or edit fields in the Kirby backend. In addition, it must be possible to make changes in certain configuration files. Multilingualism is a must. Certain fields must be shown or hidden depending on the context. Amounts must be calculated. Presumably, this is possible anyway with the Kirby block and field concepts as custom elements. The data must be sent as a confirmation email and as an organiser email upon submission and written to a database. Of course, the builders don’t have to provide all of this, but they do have to offer concepts for it.

Thanks!