tested shared Vuex store, created d8 userblock, enabled JSONAPI module

config/sync/block.block.userblock.yml

@@ -0,0 +1,20 @@
+uuid: f6ac7bc7-be23-4375-a237-1d9a36edb17e
+langcode: en
+status: true
+dependencies:
+  module:
+    - user_block
+  theme:
+    - materiotheme
+id: userblock
+theme: materiotheme
+region: header_right
+weight: 0
+provider: null
+plugin: user_block
+settings:
+  id: user_block
+  label: 'User block'
+  provider: user_block
+  label_display: visible
+visibility: {  }