Installing Code From Github To Shopify Theme Files

Good Morning To You All,

We just have a quick question in relation to integrating code from Github, into Shopify files.

Please forgive me here, as we are just wanting to confirm the installation process for Shopify. We are conversant with WordPress and other similar CRM’s, but as Shopify has a different structure entirely, installing code is a little bit different.

We are currently trying to install the lazy sizes script, and other scripts that will defer, eliminate and reduce scripts and CSS, (all Lighthouse scripts), that are currently slowing down the theme, and as the site does not belong to us, we cannot locally connect Github to our clients’ site to import the code.

We would be grateful if there was anyone that could guide us on how we install code on Shopify, such as whether we need to create a new file and then add the code that way, etc.

Thanking you in advance,

Creatively Smart Team