Please help… Embedded video

In an attempt to fix my problem myself, I found the following post,
https://www.ads-software.com/support/topic/182098?replies=3

The string that it says I need to replace,
<?php the_excerpt(‘Read the rest of this entry »’); ?>
doesn’t exist in my index.php. What do I do? Should I just include this line? If so, where would it go?

Please help!

Thanks!
Tracy Bookman
https://www.tracybookmanphotography.com/blog