Illegal string offset warning in cf7 sms tab

hi. im getting these errors in cf7 forms sms tab:

Warning: Illegal string offset 'phone' /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 63

Warning: Cannot assign an empty string to a string offset in /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 63

Warning: Illegal string offset 'message' in /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 66

Warning: Cannot assign an empty string to a string offset in /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 66

Warning: Illegal string offset 'phone' in /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 69

Warning: Cannot assign an empty string to a string offset in /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 69

Warning: Illegal string offset 'message' in /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 72

Warning: Cannot assign an empty string to a string offset in /public_html/wp-content/plugins/wp-sms/includes/class-wpsms-integrations.php on line 72

And also this type of errors appear in all fields for numbers and massage :

<br /><b>Warning</b>: Illegal string offset ‘phone’ in <b>/public_html/wp-content/plugins/wp-sms/includes/templates/wpcf7-form.php</b> on line <b>10</b><br />

how can i fix this?