Hey Vini,
Did you verify your sendgrid key is valid? Also verify if your config looks like the below in plugins.js
email: {
config: {
provider: 'sendgrid',
providerOptions: {
apiKey: env('SENDGRID_API_KEY'),
},
settings: {
defaultFrom: 'hello@email.com',
defaultReplyTo: 'hello@email.com',
},
},
}