How I can add breadcrumbs in my blog?

Ok so edit that to this:

.rank-math-breadcrumb {
    background-color: #E4E2DD;
    display: inline-block;
    padding: 5px 10px;
    border-radius: 10px;
}

Then add this:

.rank-math-breadcrumb p {
    margin-bottom: 0;
}
.rank-math-breadcrumb span.last {
    font-weight: 700;
}

These are really questions that should be handled by the plugin support as it's unrelated to the theme.

Thanks, for the help! Leo

No problem :)