I can show WorkflowDesigner tab

I

src/assets/main.css

@@ -42,6 +42,10 @@
     transition: opacity 0.2s ease;
 }
 
+.mmt-selected {
+  background-color: var(--color-base-300);
+  border-radius: .25rem;
+}
 
 .icon-32 {
     width: 32px;