ACCESSIBILITY CHECKER ERRORS

Hi, how can we fix the accessibility error ‘EMPTY FORM LABEL’ from wave.webaim.org ?

<label class=”image-replace lrm-email lrm-ficon-mail” title=”Email or Username”></label>
<label class=”image-replace lrm-password lrm-ficon-key” title=”Password”></label>
<label class=”image-replace lrm-username lrm-ficon-user” for=”signup-username” title=”Username*”></label>
<label class=”image-replace lrm-username lrm-ficon-user” for=”signup-login” title=”Login”></label>
<label class=”image-replace lrm-username lrm-ficon-user” for=”signup-last-name” title=”Last name”></label>
<label class=”image-replace lrm-email lrm-ficon-mail” for=”signup-email” title=”Email*”></label>

thanx in advance

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