How to install?
Lightning will not work at local computer, only at real server with real domain name.
Important! Before using Lightning disable or remove all caching and optimization extensions/mods – if you have any. They may cause conflicts and will make total speed slower. Lightning speeds up every aspect in more effective way then competitive extensions.
Third party WebP extensions will not work properly with page caching, so remove them if you have any. Lightning includes its own WebP support by default.
Lightning converts all product links to the canonical form shop.com/product-seo-url so that each product has only one URL for greater efficiency. If this does fit you for some reason, activate Disable products links unification option in Lightning Troubleshooting settings.
So, you have
If you have JOURNAL theme, follow JOURNAL2 or JOURNAL3 Recommendations.
If the storefront doesn't open or display an error after Lightning install, try to activate Disable template optimization option in Lightning Troubleshooting settings.