Update OS without updating to newest operating system

Hello,
I have a TI-Nspire CX CAS Version 4.3.0.702 and I would like to update to 4.4 or 4.5 because I want to install ndless. However if I updated it using the official website I would get Version 5.1. Is there any way for me to update it to a newer version, that isnt the newest version?
I would be thankfull for any help I could get!
I have a TI-Nspire CX CAS Version 4.3.0.702 and I would like to update to 4.4 or 4.5 because I want to install ndless. However if I updated it using the official website I would get Version 5.1. Is there any way for me to update it to a newer version, that isnt the newest version?
I would be thankfull for any help I could get!