You can use this plugin for .html extension https://wordpress.org/plugins/html-in-url/
And for slashes you should create page of ‘keyword1’ and ‘keyword2’ and make keyword2 as a parent page.
then u will get the slash url keyword1/keyword2
You can use this plugin for .html extension https://wordpress.org/plugins/html-in-url/
And for slashes you should create page of ‘keyword1’ and ‘keyword2’ and make keyword2 as a parent page.
then u will get the slash url keyword1/keyword2