The software does not currently model term linked CI cover. This is in queue for future development.
In the meantime, enter the policy coverages on their respective screens, being sure to account for the premiums on only one of the two screens so as not to double account for the expense. If this is is joint CI cover, enter separate policies on the Critical Illness screen for both client and spouse/partner.
Be sure that the term on all policies match.
CI cover will only pay out in scenarios where you model a critical illness by dragging a Critical Illness event onto the timeline on the software's Time screen. You will find this event to the right side of the Time screen's Events palette.
Also note that if you are running a scenario for critical illness, be sure to move the premium to the CI policy and remove the term policy from the plan, assuming that cover and premiums from the two policies combined end after the CI benefit payout.
Try entering the CI aspect of the policy on the Protection Critical screen, linking it to the same debt. This indicates that the policy would pay upon critical illness or death, depending on which were to happen first while the policy is still active.
When entering the CI cover, be sure that the selected start event and the policy's term match those set for the life cover. Most importantly, set the Premium on the CI policy to 0, so as not to double bill your client for the coverage. You mention that this is joint cover. There is no concept of joint CI cover in the software, so presumably, you would need to make an entry for the client and another for the co-insured.
Incidentally, CI payouts are only triggered by the Time screen's drag-and-drop Critical Illness events. This special modelling event would normally be used only in scenarios.
If you were to model the payout from the CI policy in a scenario, be sure to delete the second of the two CI entries. You would also need to switch the policy premium from the Term & Endowment screen to the Critical Illness screen and delete the life policy. The two/three policies aren't actually linked, so the life cover would remain in the plan even after the CI payout and the assumption is that the policy pays out on critical illness or death, but not twice, on both events.
Please note that there isn't an option to index the sum assured for Critical Illness, at present. One can model Critical Illness as a 'decreasing term' (i.e. mortgage protection) policy, but there is no option to escalate at present. As such, one would need to tailor the sum assured, as appropriate, to the particular scenario, if you're wanting to model a pay-out.