Token não esperado | Performance Web I: otimizando o front-end

Eae galerá, suave? É o seguinte, está aparecendo que <DOCTYPE html> não é uma coisa esperada como poder ver abaixo:

C:\Users\User>uglifyjs C:\Users\User\Desktop\serviçosdeprogramação\Luiz\site\index.html
Parse error at C:\Users\User\Desktop\serviçosdeprogramação\Luiz\site\index.html:1,0
<!DOCTYPE html>
^
ERROR: Unexpected token: operator «<»
    at JS_Parse_Error.get (eval at <anonymous> (C:\Users\User\AppData\Roaming\npm\node_modules\uglify-js\tools\node.js:18:1), <anonymous>:71:23)
    at fatal (C:\Users\User\AppData\Roaming\npm\node_modules\uglify-js\bin\uglifyjs:470:27)
    at run (C:\Users\User\AppData\Roaming\npm\node_modules\uglify-js\bin\uglifyjs:405:9)
    at Object.<anonymous> (C:\Users\User\AppData\Roaming\npm\node_modules\uglify-js\bin\uglifyjs:284:5)
    at Module._compile (node:internal/modules/cjs/loader:1083:30)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1112:10)
    at Module.load (node:internal/modules/cjs/loader:948:32)
    at Function.Module._load (node:internal/modules/cjs/loader:789:14)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:72:12)
    at node:internal/main/run_main_module:17:47

Help me!!!