How to show the value of Z in the forest plot？ (Meta)

Question

I'm using the (meta) package in R to analyze a meta-analysis. I am trying to create a forest plot but I can't create a line at the bottom of the forest plot to describe the total effect statement.

Does anyone know of a solution or have any ideas? Here is the detail of my coding.

m1 <- metacont(n.e,mean.e,sd.e,n.c,mean.c,sd.c,data=md,sm="MD",random = FALSE,fixed = TRUE)
forest(m1,
   family="sans",
   studlab = paste(study),
   fontsize=12.5,
   label.e = "Recurrence",label.c = "Non-Recurrence",
   lwd=1,
   col.diamond.random="black",
   col.diamond.lines.random="black",
   comb.random=FALSE,
   comb.fixed=TRUE,
   col.square="#2cafb2",
   col.square.line="black",
   col.study="black",
   Ity.random=2,
   plotwidth="8cm",
   colgap.left="1cm",
   layout ="RevMan5")

And I want to show tlike this.

I can only find the fixed effect at the bottom of the forest plot. I hope that I can find a solution to show the overall effect of the Z like the picture.