Here is the RAW url I use to delegate:

https://v2.steemconnect.com/sign/delegateVestingShares?delegator=fulltimegeek&delegatee=fulltimeangel&vesting_shares=111%20SP

• Replace fulltimegeek with davedickyyall
• Replace fulltimeangel with delegatee's name
• Replace 111 with how much SP you're delegating

You will need your master password or active key to make the transaction happen.