Hi! Me again… 
I included the spinner, but I can´t see it.
I imported the WebKit into DetailViewController.
I also added WebKit.framework under
General -> Targets -> Frameworks, Libraries and embedded Content
(But: My app only runs if I set WebKit.framework here to “Do not embed”… otherwise my app crashes)
FOLLOWING I POST MY DEBUGGING AREA, MAYBE IT MAKES SENSE TO SOMEBODY???
020-12-15 20:26:13.519075+0100 News1[7409:4202180] [] nw_protocol_get_quic_image_block_invoke dlopen libquic failed
2020-12-15 20:26:16.844333+0100 News1[7409:4201791] WF: === Starting WebFilter logging for process News1
2020-12-15 20:26:16.844617+0100 News1[7409:4201791] WF: _userSettingsForUser : (null)
2020-12-15 20:26:16.844801+0100 News1[7409:4201791] WF: _WebFilterIsActive returning: NO
2020-12-15 20:26:26.384925+0100 News1[7409:4201791] [Loading] 0x7fb803047820 - [pageProxyID=6, webPageID=7, PID=7416] WebPageProxy::didFailLoadForFrame: frameID = 52, domain = NSURLErrorDomain, code = -999
2020-12-15 20:26:26.840144+0100 News1[7409:4201791] [Loading] 0x7fb803047820 - [pageProxyID=6, webPageID=7, PID=7416] WebPageProxy::didFailLoadForFrame: frameID = 52, domain = NSURLErrorDomain, code = -999
2020-12-15 20:26:27.201189+0100 News1[7409:4201791] [assertion] Error acquiring assertion: <Error Domain=RBSAssertionErrorDomain Code=3 “Required client entitlement is missing” UserInfo={RBSAssertionAttribute=<RBSDomainAttribute| domain:“com.apple.webkit” name:“MediaPlayback” sourceEnvironment:"(null)">, NSLocalizedFailureReason=Required client entitlement is missing}>
2020-12-15 20:26:27.202489+0100 News1[7409:4201791] [ProcessSuspension] 0x1132b8960 - ProcessAssertion: Failed to acquire RBS MediaPlayback assertion ‘WebKit Media Playback’ for process with PID 7416, error: Error Domain=RBSAssertionErrorDomain Code=3 “Required client entitlement is missing” UserInfo={RBSAssertionAttribute=<RBSDomainAttribute| domain:“com.apple.webkit” name:“MediaPlayback” sourceEnvironment:"(null)">, NSLocalizedFailureReason=Required client entitlement is missing}
2020-12-15 20:26:27.208954+0100 News1[7409:4201791] [assertion] Error acquiring assertion: <Error Domain=RBSAssertionErrorDomain Code=3 “Required client entitlement is missing” UserInfo={RBSAssertionAttribute=<RBSDomainAttribute| domain:“com.apple.webkit” name:“MediaPlayback” sourceEnvironment:"(null)">, NSLocalizedFailureReason=Required client entitlement is missing}>
2020-12-15 20:26:27.213555+0100 News1[7409:4201791] [ProcessSuspension] 0x1132b8990 - ProcessAssertion: Failed to acquire RBS MediaPlayback assertion ‘WebKit Media Playback’ for process with PID 7409, error: Error Domain=RBSAssertionErrorDomain Code=3 “Required client entitlement is missing” UserInfo={RBSAssertionAttribute=<RBSDomainAttribute| domain:“com.apple.webkit” name:“MediaPlayback” sourceEnvironment:"(null)">, NSLocalizedFailureReason=Required client entitlement is missing}
2020-12-15 20:26:27.666338+0100 News1[7409:4201791] [assertion] Error acquiring assertion: <Error Domain=RBSAssertionErrorDomain Code=3 “Target is not running or required target entitlement is missing” UserInfo={RBSAssertionAttribute=<RBSDomainAttribute| domain:“com.apple.webkit” name:“Background” sourceEnvironment:"(null)">, NSLocalizedFailureReason=Target is not running or required target entitlement is missing}>
2020-12-15 20:26:27.666601+0100 News1[7409:4201791] [ProcessSuspension] 0x1132feac0 - ProcessAssertion: Failed to acquire RBS Background assertion ‘WebProcess Background Assertion’ for process with PID 7416, error: Error Domain=RBSAssertionErrorDomain Code=3 “Target is not running or required target entitlement is missing” UserInfo={RBSAssertionAttribute=<RBSDomainAttribute| domain:“com.apple.webkit” name:“Background” sourceEnvironment:"(null)">, NSLocalizedFailureReason=Target is not running or required target entitlement is missing}
2020-12-15 20:26:57.451445+0100 News1[7409:4201791] Could not signal service com.apple.WebKit.WebContent: 113: Could not find specified service