ggplot2 not recognising column names in function

My goal is to have a function in which can input specific column and df names, in order to output graphs in a consistent format. However, I am having some trouble with creating functions using ggplot2, because of problems with column name recognition. So far, I haven't had any success with any of the fixes people have proposed in other questions addressing this issue.

Using a test dataset as an example, this is what I tried first

set.seed(123)
MYdata1 <- data.frame(Time = 1:1000,
                    Zscore = rnorm(1000))
plot_testassess <- function(data1,xvar = "Time",yvar = "Zscore"
){ggplot(data = data1, aes(.data[[xvar]], .data[[yvar]]))}
plot_testassess(MYdata1,Time,Zscore)

However, I kept getting the error

> Error in enquo(x) : object 'Time' not found

so then I tried aes_string, like this :

plot_testassess <- function(data1,xvar = "Time",yvar = "Zscore"
){ggplot(data = data1, aes_string(x=xvar,y=yvar))}
plot_testassess(MYdata1,Time,Zscore)

But in this case I got the following error.

> Error in aes_string(x = xvar, y = yvar) : object 'Time' not found

I am at a loss as to how to make ggplot2 recognise that my column variables are not objects. Does anyone have any thoughts?

library(ggplot2)
set.seed(123)
MYdata1 <- data.frame(Time = 1:1000,
                      Zscore = rnorm(1000))

You can make your function work, by putting quotation marks around the
variable names in the function call. (I added geom_line() to you function
so we get a visible result; nothing else is changed here.)

plot_testassess <-
  function(data1,
           xvar = "Time",
           yvar = "Zscore") {
    ggplot(data = data1, aes(.data[[xvar]], .data[[yvar]])) +
      geom_line()
  }
plot_testassess(MYdata1, "Time", "Zscore")

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If you prefer to be able to provide the variable names without quotation
marks you can drop the .data[[]] and embrace xvar and yvar with {{}}.

plot_testassess_nse <-
  function(data1,
           xvar = "Time",
           yvar = "Zscore") {
    ggplot(data = data1, aes(
        {{xvar}}, 
        {{yvar}}
      )) +
      geom_line()
  }
plot_testassess_nse(MYdata1, Time, Zscore)

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