Let me check that. Your link leads to another link which has this text:
"For third party deposits, please send documents for both parties as well as a front & back, colour copy of the credit card used, showing: full name, expiration date, first 4 and last 4 digits of the credit card number and a signed POA (Power of Attorney) Form."
So, evidently at least one licensed broker permits 3rd party deposits - If and only if IDs of both parties are submitted along with a Power of Attorney form authorizing the account holder to use the 3rd party's funding source.
This is the first time I've ever seen such a thing. On the other hand, it makes sense - If and ONLY if the 3rd party provides ID and signs a POA permitting it. The vast majority of 3rd party funding lacks that extra ID and POA, plus the bulk of licensed brokers have a blanket prohibition on 3rd party funding.
Any broker that would permit 3rd party funding without a POA is likely to be a deposit-only bucketshop. After all, if a broker plans to steal the money, they don't care whether the person depositing was using someone else's account or not.