From the plugin settings, select Clickatell and choose SMS API.
Now, follow these steps:
1- Go to https://app.clickatell.com/products/channels/sms and click on Activate Channel.
2- Visit the page https://app.clickatell.com/my-workspace/sms and click on New SMS setup.
3- Choose API and select if you want to send One-Way or Two-Way messages and click Next.
4- Choose Basic HTTP API and Create a new HTTP API, then click on Next.
5- Complete the form with the required data and click on Next.
6- Now copy and paste the generated key to the field Clickatell API Key in the plugin settings and click on Complete.
In case you have a Clickatell account previously registered, select Developers Central (Legacy).
Now, follow these steps:
1- Go to https://central.clickatell.com/api/add.
2- Click on the Add HTTP API button.
3- Copy and paste the API ID with the username and password to the related fields in the plugin settings.