PWA ‑ iOS & Android Mobile App

How can we enable Standalone mode in Chrome? Please answer. Thanks in advance, we are paying for app and it is good, but we want nice standalone in Chrome otherwise we need another app :-(

Edit: Great app... But standalone is not functioning in Chrome up now ...and it is hard to us to install and pay other app beside this which we want only to maintain acces to customers whoch allready installed this app... Only 1 pwa can work because of proxy... We will deinstall it at the end because od standalone Chrome issue ... And send excuse to our custommers who installed it .

Edit2: after more than half year still not resolved problem for standalone mode in Chrome... We will be more than happy to use another app and pay for both but there is only one proxy and all visitor which instaled via this app already would not have access anymore... Very disapointing... We are still hopping for resolving issue and editing to some better rating