title: laravel current timestamp in migration with carbon
body: <p>I want to display created_at as a timestamp like this :</p>
  <p><code>created_at : 1625501162</code></p>
  <p>so this is my created_at column in migration:</p>
  <p><code>$table-&gt;string('created_at')-&gt;Carbon::now()-&gt;timestamp;</code></p>
  <p>Now I want this field to be created automatically when a new record is created and record the current time. so when i change the line to this :</p>
  <p><code>$table-&gt;string('created_at')-&gt;useCurrent(Carbon::now()-&gt;timestamp);</code></p>
  <p>gives me this error :</p>
  <p><code>Method call is provided 1 parameters, but the method signature uses 0 parameters</code></p>
  <p>so how can i fix this problem?</p>
  <p>What other ways do you suggest for timestamp created_at and store it automatically?</p>