Problem with modal Bootstrap and htaccess

I am developing a project with bootstrap and it requires to use htaccess to format url, ok, in the main page I work perfectly the modal but when you enter a page the modal no longer works:

this is the code I use for modal:

<a href="" data-toggle="modal" data-target="#login">Ingresar</a>

I read in another post in English q Because you change the base route, you have to fix that, with:

<base href="/subdomain/">

or

<base href="http://www.domain.com/subdomain/">

within <header>

but not like that