ruby, 90 bytes

Result

WA

Duration

973ms

Code [DL]

t=gets.index "T"
s=1
s+=1 while !u=gets.index("K")
k=" "*u
puts k+"="*(t-u)+"
"+(k+"=
")*s

stdin

                                      T           
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                               K                  

stdout

                               =======
                               =
                               =
                               =
                               =
                               =
                               =
                               =
                               =
                               =
                               =
                               =
                               =
                               =
                               =

stderr

strace

11    execve("/bin/sh", ["/bin/sh", "/root/script", "/volume/CODE"], 0x7ffd65b69cc0 /* 9 vars */) = 0
13    execve("/usr/local/ruby-2.6.3/bin/ruby", ["/usr/local/ruby-2.6.3/bin/ruby", "/volume/CODE"], 0x560519427d60 /* 9 vars */ <unfinished ...>
12    execve("/bin/cat", ["cat", "-"], 0x560519427d40 /* 9 vars */) = 0
12    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=12, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
13    <... execve resumed> )            = 0
13    +++ exited with 0 +++
11    --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=13, si_uid=0, si_status=0, si_utime=5, si_stime=3} ---
11    +++ exited with 0 +++