Hey I'm looking to buying Bitcoin in amount of $5-10 M .
Seller must pass Satoshi text. If you got any advice or leads, it'll be appreciated.
What do you mean by seller must pass Satoshi text? At sych amount that wrote you need to use the OTC service provided by a crypto exchange. Since your account is brand new I don't think anyone would trust you here. Moreover those who have that value of Bitcoin will never sell it as they know the potential of Bitcoin.
Perhaps our OP should consider buying spot exchange traded funds, ETFs, that is available since before the halving and gaining adoption currently.
There's no need for much alarms also because this is where a trusted broker or exchange service is needed and it would be a bad idea if our OP doesn't have much knowledge on the subject of Bitcoin and cryptocurrencies in general and still decide to invest in it.