Added imports

widget_huli/forum/models.py

 from django.db import models
 from django.urls import reverse
+from dashboard.model import WidgetUser
 
 # Create your models here.
 class ForumPost(models.Model):
     title = models.CharField(max_length=50)
     body = models.TextField()
-    author = models.CharField(max_length=50)
+    author = models.ForeignKey(
+        WidgetUser,
+        on_delete=models.CASCADE
+    )
     pub_datetime = models.DateTimeField()
     
     def __str__(self):