How to solve: Error: Can only be used in a quasiquoted argument?

Hi, I am trying to run some calculations with processR from shiny app and lavaan at the moment and I repeatedly get the error message: "Can only be used in a quasiquoted argument".
Does anyone have experience with this? What am I doing wrong?

Find an example below:

finance ~~ finance.varfinance
finance ~ ~finance.var * finance
indirect :=(a)
(b1+b2*finance.mean)
Error: := can only be used within a quasiquoted argument

Thank you in advance!