"Unable to Verify App" - iPhone error message from Xcode app testing

I am trying to deploy an app that I have coded on my Mac in Xcode to my personal iPhone only. I have an Apple Developer account but am NOT in the program since all I currently need is testing the app on my device only. I have followed the instructions as per this video https://www.youtube.com/watch?v=bqh6YaMxgbE, but have an issue at 6:55 in the video where I indeed "Trust" the certificate for my app in iPhone settings, followed by hitting the run button in Xcode for my iPhone (which is connected to my Mac via a lightning cable and recognized), and my app DOES INDEED get trusted; however, there is an ADDITIONAL thing to do for me on my iPhone: click the "Verify App" button. When I do so, nothing happens. If I re-run the app using Xcode, there is

• an error on my Mac saying, "The operation couldn’t be completed. Unable to launch . . . because it has an invalid code signature, inadequate entitlements or its profile has not been explicitly trusted by the user" and...
• an error on my iPhone saying, "Unable to Verify App" -- "An Internet connection is required to verify trust of the developer "Apple Development: xxx@gmail.com..." This app will not be..."

Also, I have an excellent Internet connection. I am not sure why the app cannot get verified. I have an iPhone 13 Pro running iOS 16.4.1 (a) and a Mac running MacOS Ventura. Please assist! I really need to get my app on my phone and test it! Thanks!