Good day! We looked at your website and noticed all the features of PWA are working perfectly like Add to Homescreen, Splash screen, Offline Caching, Theme color etc.
Steps to troubleshoot:
1) Can you please let me know whether you have installed the PWA earlier for the same website on your device? If yes, please uninstall and clear the cache. You can easily check this by tapping the browser menu (the three dots at the right corner of your Chrome Browser), if its added earlier you can see “Open ideal” there, otherwise it will be “Add to HomeScreen“.
2) Can you please let me know whether you have cleared the browsing data on browser? Here’s the steps to clear the browsing data by tapping the browser menu on Google Chrome for Android > Settings > Privacy > Clear browsing data > Select Advanced tab > from that select options like Browsing history, Cookies and site data, Cached images and files, Site settings and tap Clear Data.
3) Can you check any other PWA website’s (you can check our website superpwa.com) and let me know whether the Add to Home screen prompt occurs or not on your browser? If not, its because of the low memory storage limit within your device for browser. Free up some space and clear the cache to test it again.
4) Also please confirm whether you are testing upon Google Chrome for Android or on iOS device?
Looking forward to hearing your thoughts.