The following was helpful.

https://stackoverflow.com/questions/59407003/set-focus-text-field-inside-dialog-when-dialog-opened

By accessing $refs after a short delay when opening the dialog, it worked successfully.

w}atcd}hi:a}li{of}gs,:evtt2faTh0ulii0nums)cee.;t)o$iuro{ten(f((sv).anl=au>mee){.f{ocus();