i don't have a software update option on my mac

This means that you've reached the highest version of the system you are using. Moving to a higher system is an upgrade, and is handled by the App Store. What you can upgrade to is determined by your model of Mac: if you post that here someone can check. Go to the Apple Menu, choose 'About this Mac', click 'System Report' and quote the model version shown in the second line where it says 'Model Identifier' - two numbers separated by a comma.

avanav1345 wrote:

i cant update my laptop please help

>About this Mac>Software update.

older macOS— installer backups on this server:

https://support.apple.com/en-gb/HT211683

verify you are using the Safari browser to download/initiate the macOS links.