Look at forms.saveForm
pipeline in the Sitecore.ExperienceForms.Pipelines.Client.config
configuration file; the default settings are
<forms.saveForm>
<processor type="Sitecore.ExperienceForms.Client.Pipelines.SaveForm.CreateModels, Sitecore.ExperienceForms.Client" resolve="true" />
<processor type="Sitecore.ExperienceForms.Client.Pipelines.SaveForm.GenerateNames, Sitecore.ExperienceForms.Client">
<defaultItemName>Form Item</defaultItemName>
</processor>
<processor type="Sitecore.ExperienceForms.Client.Pipelines.SaveForm.CheckAccessRights, Sitecore.ExperienceForms.Client" resolve="true" />
<processor type="Sitecore.ExperienceForms.Client.Pipelines.SaveForm.UpdateItems, Sitecore.ExperienceForms.Client" resolve="true" />
</forms.saveForm>
item:saved
oritem:saving
?