Intelephense Language server adjust targeted PHP version

[isaiahfisher]

I am trying to adjust the targeted php version of the intelephense language server being used, but I am not having any luck. The language server appears to continue to reject syntax from php version 8.3 even with the following vimrc configuration:

call LspAddServer([#{
        \   name: 'intelephense',
        \   filetype: ['php'],
        \   path: '/usr/local/bin/intelephense',
        \   args: ['--stdio'],
        \   initializationOptions: #{ intelephense: #{ environment: #{ phpVersion: '8.3'}}}
        \ }])

Am I missing something here, or is the initializationOptions setting not being sent over to the language server properly?