Impossibile aggiungere plug-in o piattaforma al progetto ionic3: ionic3, cordova-plugins

Non appena eseguo il comando cordova aggiungere piattaforma o plugin per cordova ionica https://github.com/moust/cordova-plugin-videoplayer.git Ottengo l'errore indicato di seguito.

**(node:5072) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejec
tion id: 1): CordovaError: Cordova does not know add; try `cordova help` for a l
ist of all the available commands.
(node:5072) [DEP0018] DeprecationWarning: Unhandled promise rejections are depre
cated. In the future, promise rejections that are not handled will terminate the
Node.js process with a non-zero exit code.**

Ho provato la cordova degradante ma non ha funzionato. Come risolvo questo problema?

MODIFICARE : La piattaforma Cordova aggiunge Android mi ha dato errore:

Using cordova-fetch for cordova-android@~7.0.0
(node:3444) UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejec
tion id: 1): CordovaError: Failed to fetch platform cordova-android@~7.0.0
Probably this is either a connection problem, or platform spec is incorrect.
Check your connection and platform name/version/URL.
Error: cmd: Command failed with exit code ENOENT
(node:3444) [DEP0018] DeprecationWarning: Unhandled promise rejections are depre
cated. In the future, promise rejections that are not handled will terminate the
Node.js process with a non-zero exit code.

risposte:

La riga di comando che hai inserito è sbagliata. La linea di comando è

$ ionic cordova platform add android

o

$ cordova platform add android