Defining Vector Layer Name with PyQGIS

Question

The goal of my python script is to get geographic data from an XML file and transform it into a vector layer. This task is successful but each of my layers have the same name... and I can't find a way to rename these layers with a field of my attribute table.

This is my code:

def espaces(code):
node1 =root.find('EspaceS')
node2 =root.find('PartieS')
node3 =root.find('ServiceS')
node4 =root.find('VolumeS')
node5 =root.find('FrequenceS')
for item in node1:
    if get_text(item,'TypeEspace')==code:
        layer = QgsVectorLayer('MultiPolygon?&field=PK:integer(3)&field=NOM:string&field=Horaire:string&field=PLAFOND:string&field=PLANCHER:string&field=CLASSE:string&field=FREQ:string&crs=epsg:2154',code,"memory")
        feat = QgsFeature(layer.fields())
        feat['PK']=get_attrib(item,'pk')
        
        for item2 in node2:
            feat['NOM']=item2.find('Espace').attrib['lk'][5:-1]+get_text(item2,'NomPartie')
            if item2.find('Espace').attrib['pk']==get_attrib(item,'pk'):
                for item3 in node3:
                    if item3.find('Espace') is not None:
                        if item3.find('Espace').attrib['pk']==item2.find('Espace').attrib['pk']:
                            for item5 in node5:
                                if item5.find('Service').attrib['pk']==item3.attrib['pk']:
                                    feat['FREQ']=get_text(item5,'Frequence')
                                    break
                            break
                for item4 in node4:
                    if item4.find('Partie').attrib['pk']==item2.attrib['pk']:
                        feat['Horaire']=get_text(item4,'HorCode')
                        feat['CLASSE']=get_text(item4,'Classe')
                        feat['PLAFOND']=get_plafond(item4)
                        feat['PLANCHER']=get_plancher(item4)
                        break
                GEO=[]
                GEO=get_text(item2,'Geometrie').split(chr(10))
                PTS=[]
                for i in range(0,len(GEO)-1):
                    PTS.append(Coords(GEO[i]))
                feat.setGeometry(QgsGeometry.fromPolygonXY([PTS]))
                layer.dataProvider().addFeatures([feat])
                layer.name
        layer.setOpacity(0.5)
        QgsProject.instance().addMapLayer(layer)
        

#CTL espaces('CTL')

I would like to put the field 'Nom' as the name of each of my layers

Can someone tell me how to do this ?