Generalized linear mixed model and significance level

[AlessandroMacario]

Hello,
In linear mixed models, the variance estimates (random slope and/or intercepts + residuals) come with  the Wald statistic test and its significance value. I was wondering why it is not the case in Generalized linear mixed models where the covariance parameter table represents estimates+SE+CI but not W-test.
Is there a way to have the W test + p-value?
Thanks in advance for your reply
Alessandro