In the Jira Cloud new view, there is no field to vote on a development request. While Atlassian is working on it, this article helps you to get back to the old view and vote on the required development request.
The following steps helps you to switch to the Jira Cloud old view:
Click the Profile icon on the bottom left corner once you log in to Jira Cloud instance.
Select Settings as shown:
Toggle the button, in New Jira issue view under Jira labs, off as shown:
Now, you can vote on any dev ticket through the old view.
All the Jira Cloud instances, that you have access to, uses the Jira old view once the specified changes are done. This change effects only your user across all issue types.