I was facing the similar issue, Mine is android phone (real me ). My problem is solved when i open additional settings and allowed OTG connection.
For connection i have used type c to otg connector and then micro usb cable. Below is the sample link from amazon.
1. https://www.amazon.in/Congo-Transfer-Smartphone-Compatible-Connector/dp/B082ZBZHFB/ref=sr_1_1_sspa?crid=3G0HN4XF3JHBL&dchild=1&keywords=type+c+to+otg+connector&qid=1603120034&sprefix=type+c+to+o%2Caps%2C300&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyQksyNUhESUxJU0RXJmVuY3J5cHRlZElkPUEwODUwNDg1N1ZIWUw3SVVZM1BCJmVuY3J5cHRlZEFkSWQ9QTA5MTEzMDExVjVVUjNDS1c2REYxJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
So for all latest android devices, There must be a permission issue. For me i did tried using Aux cable but it didn't work. In i still finding how to open app mode in keyboard (hot key or any key combination). If any one know please post it over here.
