One of the dependencies, the Icens
package, has been removed from CRAN, but you can install it from Bioconductor and then try to install LTRCtrees
if (!requireNamespace("BiocManager", quietly = TRUE))
install.packages("BiocManager")
BiocManager::install("Icens")
Note: Please do not post screenshots, they are considered a bad practice here, post formatted code instead, here you can find how to do it.