The iSend Help Center explains step by step how to send SMS and Viber

Trial account, first send, Sender ID.

• How to get a trial account and what it includes
• How to add team members to my account and what each role does
• How to set the Sender ID on my account

Characters, scheduling, personalization, test send.

• How to insert the name and other fields into the message
• How to schedule a send for a specific time
• How to send my first SMS campaign

Import from Excel, groups, opt-in and opt-out, STOP.

• How to add custom fields to contacts
• How to import contacts from Excel or CSV
• How to create and organize contact groups

Appointments, birthdays and name days, auto-reply.

• How automations work in iSend
• How to send automatic birthday and name day wishes
• How to connect Google Calendar and how the sync works

Plugin installation, order updates, abandoned cart.

• How to enable abandoned cart SMS
• Which SMS the plugin sends for each order status
• How to connect the WooCommerce plugin to your iSend account

API key, sending, delivery statuses, examples.

• How to get an API key and send your first SMS with curl and PHP
• How to send SMS from SoftOne documents

What you need, image and button, SMS fallback.

• How to send a Viber message and what happens if the recipient does not have Viber

What each status means and why a message was not delivered.

• Why my SMS was not delivered and what each status means

Credits, credit rollover, grace period, VAT.

• How credits are calculated and what happens to those left over

GDPR in practice, sending hours, what is not allowed.

• At what hours is it allowed to send marketing SMS