I followed step by step the instuctions given by @Louis in his live video (Going live - Filter block, classes and going free? - YouTube) to create a filter (every step I made was identivcal to him’s).
Everything ran well up to the display of categories in the page. Backend, the product categories are displayed, but frontend the categories are not. So, I set the ID of the query in the filter form, but it is not efficient.
Thank you to help me to fix that.
Edit: I thought that I misunderrstood something and made a mistake, but everything is similar to the video…