Via a link

1: Setup scan via Website

You have to setup this before the customer booking event.

Go to Events >> Settings >> General >> General Settings >> "Scan qr code with": Website or Application

2: Register an account for Staff

Example: Register an user in website like: Username: demo Password: demo

3: Setup "Staff Member" per event

Edit an Event >> go to "Staff Member" tab >> Insert Username of Staff

4: Scan QR Code

Step 1: The Staff have to login website

Step 2: Insert a link to scan QR Code in browser like:

https://your-domain/?check_qrcode=number-QR-Code&post_type=eventyour-domain

your-domain: Replace it with your domain.

number-QR-Code: Replace it with QR Code in ticket of customer.

Example:

https://demo.ovathemewp.com/meup/?post_type=event&check_qrcode=3b57d7c86a7b315756b8df11fba94acf

Step 3: View validate of ticket.

After check ticket via URL, website will display valid of ticket: Valid or Invalid with some information.

The ticket is Valid

Ticket is invalid

5: Edit output of template

If you want to edit some information in step 3, you can edit template in child theme:

Copy file 
plugins/eventlist/templates/ticket-info.php 
to 
themes/meup-child/eventlist/ticket-info.php