The password keeps being rejected
Wi-Fi passwords are case sensitive, and printer keypads make it easy to confuse a capital I with a lowercase l, or a zero with an O. The details are usually printed on a sticker on the router itself, so read them from there rather than from memory. If the password is definitely right, your router may be set to WPA3, which older printers can't join. Switching the router to WPA2, or to a mixed WPA2 and WPA3 mode, usually clears it.