Quite simple:
<q-uploader
:url="upload"
:labels = "{add:'Selecionar arquivo',remove:'Remover',upload:'Enviar',failed:'ERRO',uploading:'Enviando'}"
:additionalFields = "[
{'name':'id_cliente','value':this.id_cliente},
{'name':'id_usuario','value':this.id_usuario},
{'name':'url','value':this.url},
{'name':'token','value':this.token},
{'name':'categoria','value':this.form.categoria},
{'name':'titulo','value':this.form.titulo},
{'name':'email','value':this.form.email},
{'name':'telefone','value':this.form.telefone},
{'name':'comentario','value':this.form.comentario},
]"
:hide-upload-button = "true"
@finish = "upload_ok"
@fail = "upload_erro"
buttonClass="bg-green-7 radius04 text-white"
ref="uploader">
</q-uploader>
then after some validation you call
this.$refs.uploader.upload();