@pietro
In general, it is recommended to avoid using the hash (#) character in URLs for SEO purposes, as search engines may not crawl or index the content after the # symbol. This is because the content after the # symbol is typically used for fragment identifier or navigation purposes within a single page, and is not considered to be a separate resource by search engines.
Instead, you can use a URL structure that uses slashes (/) to indicate hierarchical relationships between pages, or you can use query parameters (e.g., ?param=value) to pass information to the server.
If it is not possible to avoid using the # character in your URLs, you can use a technique called "hashbang URLs" to allow search engines to crawl and index the content after the # symbol. This involves adding an exclamation mark (!) after the # symbol, and rewriting the URL on the server side to make it appear as a separate resource to search engines. However, this technique is no longer commonly used, as the majority of search engines now support the use of HTML5 pushState for this purpose.
In general, it is best to use a URL structure that is simple, easy to understand, and SEO-friendly, in order to ensure that your content can be easily crawled and indexed by search engines.