The code can be pasted into the console of a browser window with an active Canvas session with the appropriate course ID and assignment ID.
let csrf = Cookies.get('_csrf_token')
let courseID = ''
let assignmentID = ''
fetch('https://fiu.instructure.com/courses/${courseID}/undelete/assignment_${assignmentID}', {
method: 'POST',
headers: {
'X-CSRF-Token': csrf
},
})
.then( res => res.json() )
.then( res => console.log(res) ) // confirmation