Valor Autocomplete

Question

Good afternoon, I would like to know how to use the value entered in the autocomplete field in my Controller, even if it is null and not a vehicle registered in the BD.

                        <p:outputLabel value="Veículo: " style="padding-right: 30px"/>
                        <p:autoComplete id="veiculo" dropdown="true" 
                            label="Veículo" required="false" placeholder="Todos" 
                            readonly="#{portariaController.tipoVeiculo == 'SEM_PLACA' || portariaController.tipoVeiculo == 'SEM_VEICULO'}"
                            value="#{portariaController.veiculo}" 
                            completeMethod="#{veiculoController.completeVeiculos}" 
                            maxResults="10" var="v" itemLabel="#{v.placa}" 
                            converter="#{entityConverter}" itemValue="#{v}" forceSelection="false" >
                            <p:ajax event="itemSelect" update=":formPrincipal:pnlVeiculo" />
                            <p:ajax event="change" update=":formPrincipal:edit"/>
                        </p:autoComplete>