OS X Yosemite- MacBook Mid 2010.

i have an iPhone X (IOS14.2) and when I tried to synchronize it with my MacBook a message tells me to install OS X 10.11.4 or later in my computer.

ma Mac has the version 10.10.5 update. when I tried to update it, a message appears saying: No updates available.

what should I do?

thanks