Accessng Opencart Theme displays this error please help

Hello greetings to everyone, I’m happy to join the forum.
however, i may need assistance on a new opencart theme i bought, it displays this error below

Fatal error: Uncaught exception ‘Exception’ with message ‘Undefined mixin text-overflow: failed at @include text-overflow; /var/www/u0535074/public_html/ on line 216’ in /var/www/u0535074/public_html/ Stack trace: #0 /var/www/u0535074/public_html/ scss_parser->throwParseError(‘Undefined mixin…’, 4709) #1 /var/www/u0535074/public_html/ scssc->throwError(‘Undefined mixin…’) #2 /var/www/u0535074/public_html/ scssc->compileChild(Array, Object(stdClass)) #3 /var/www/u0535074/public_html/ scssc->compileChildren(Array, Object(stdClass)) #4 /var/www/u0535074/public_html/ scssc->compileBlock(Object(stdClass)) #5 /var/www/u0535074/public_html/budl in /var/www/u0535074/public_html/ on line 4051

please help me thank you.

You should contact the author of the opencart theme:

Good Luck