Your training lead needs to set you as 'training' in 'paediatric colon' from their organisation admin page:
Once this is set, you will have access to the 'colon (p)' tab:
Please note that you will still have access to the adult tab(s), though you would apply through the colon (p) tab.
Any procedure on a patient aged 1-18 will automatically count towards your lifetime procedure count and 'scopes' requirements in stages 1-3.