If you missed paying for your SIP on time, you can do either of the below.
1. Make a lumpsum investment to compensate for the missed SIP.
On the Investments page, click on the Investment summary card (where the current value is shown) and select all the funds that were in the SIP > Continue > Lumpsum > Enter the amount you want to invest > Review > Confirm and Pay.
or
2. You can also modify the SIP.
On the Investments page, click on the Investment summary card (where the current value is shown) and click on the "SIP" Tab > Click on the 3 dots beside the SIP you wish to modify > Modify SIP.
Modify SIP allows you to change the date or/and the amount that will be invested from the next SIP onward. When you make changes to the SIP, the old SIP is stopped and a new one is set up with the desired changes. This won't affect your existing investments and the changes will be done only for your future SIP payments.
There is no penalty from us or mutual fund companies if you miss/fail to pay for your SIP. If you have an auto-pay enabled and you have insufficient balance on SIP date, then the bank may charge a small penalty (not done by all banks).