Hello,
First of all thanks for choosing our Theme, we are glad to be you in the WoodMart WordPress family :-).
Sorry, I don’t know what is installer.php there is no such file in our theme.
You can follow our detailed documentation on theme installation at the following link:
https://xtemos.com/docs/woodmart/installation-process/
If you are facing any difficulties then elaborate what issue you are facing with the help of some relevant screenshots to check it myself and help you out accordingly.
Best Regards.
.
