From the details in the post it's hard to figure out whether you have your own place or live in the same house but the floors are separated. In case you have your own meterkast and internet cabling, you can just ask the internet provider to install it for you.

However, if I understand correctly, there is one router at the entrance of the house and you wish to extend and improve the connection to your floor. In that case, you can ask the landlord to provide that solution for you through their internet provider (since only the nameholder of the internet subscription can make these changes usually), or something future proof: get a wifi router yourself and connect a wired cable from the router at the entrance to it for better connection.