Try using FullTypedThrows.

Alamofire.xcodeproj/project.pbxproj

@@ -2357,7 +2357,7 @@
 					"@executable_path/../Frameworks",
 					"@loader_path/Frameworks",
 				);
-				OTHER_SWIFT_FLAGS = "$(inherited) -enable-experimental-feature TypedThrows";
+				OTHER_SWIFT_FLAGS = "$(inherited) -enable-experimental-feature TypedThrows -enable-upcoming-feature FullTypedThrows";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 			};
@@ -2377,7 +2377,7 @@
 					"@executable_path/../Frameworks",
 					"@loader_path/Frameworks",
 				);
-				OTHER_SWIFT_FLAGS = "$(inherited) -enable-experimental-feature TypedThrows";
+				OTHER_SWIFT_FLAGS = "$(inherited) -enable-experimental-feature TypedThrows -enable-upcoming-feature FullTypedThrows";
 				SDKROOT = macosx;
 				SKIP_INSTALL = YES;
 			};

Source/Request.swift

@@ -1614,7 +1614,7 @@ extension DataStreamRequest.Stream {
 
 // MARK: - WebSocketRequest
 
-#if canImport(Darwin) && !canImport(FoundationNetworking) && swift(>=5.11) && hasFeature(TypedThrows)
+#if canImport(Darwin) && !canImport(FoundationNetworking) && swift(>=5.11) && hasFeature(FullTypedThrows)
 
 /// `Request` subclass which manages a WebSocket connection using `URLSessionWebSocketTask`.
 @available(macOS 10.15, iOS 13, tvOS 13, watchOS 6, *)