Are you looking to resolve the Preload Key requests shown on Google PageSpeed Insights or GTmetrix? Then you can use this code to fix the issue and put it on the Passed Audit. Alternatively, you can also use a free plugin – Autoptimize, where on the extra field, you can add links to preload for your WordPress website. Please check the tutorial video for any confusion.

Here are other tutorials to improve your GTmetrix Score:

• Add Expires Headers and Leverage Browser Caching: Click here
• For Defer Parsing of JavaScript: Click here
• Cache configuration as recommended by GTmetrix: Click here
• Loading jQuery from the Google CDN: Click here