Problems with readMeta

[ceramisaGH21]

Hello,
I am trying to do some atmospheric corrections on Landsat 8 data in Rstudio.
I have already installed RStoolbox
the problem occurs when reading the MTL

m_data <- readMeta("LC08_L1TP_008066_20210715_20210721_01_T1_MTL.txt", raw = TRUE)

Error in readMeta("LC08_L1TP_010063_20200827_20200905_01_T1_MTL.txt", :
could not find function "readMeta"

I'm using the latest version of Rstudio and it also happens with the 2021 version

Could someone help me with this problem?