I was told to update my safari search engine to the latest version , I'm concern my MacBook Air and is old - I'm think MacBook Air will not be able to handle the upgrade and the system will negatively effect the use of my laptop

I was told by Chase Bank I need to update my safari search engine( Mojave 10.14.6 ) to it's latest version if I want to use their banking customer site. I have been using The Chase site ,without a problem, for the past 12 years - I'm concerned that my MacBook Air( over 10 years old) updated Safari software will crash my laptop ?

In he past I tried previous Safari updates and had problems with my entire system . How should I proceed if I want to use Chase site

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