How to limit the number of text box characters in NSIS - nsis

Question

I want to limit the number of characters in each text box to 4 digits.
It can be implemented in C # Winform, but it is not familiar with how to use it in NSIS.
Attempted action:
I put the label and I am guiding the input to four digits.
But that's not good.
I tried to find information through the NSIS forum, but I could not find it.
Attach text box image :
text box
NSIS code:
Function Test
!insertmacro MUI_INSTALLOPTIONS_READ $0 "pageInputLicenseInfo.ini" "Settings" "State"
${If} $0 == 9 # btton
!insertmacro MUI_INSTALLOPTIONS_READ $R0 "pageInputLicenseInfo.ini" "Field 1" "State"
!insertmacro MUI_INSTALLOPTIONS_READ $R1 "pageInputLicenseInfo.ini" "Field 2" "State"
!insertmacro MUI_INSTALLOPTIONS_READ $R2 "pageInputLicenseInfo.ini" "Field 3" "State"
!insertmacro MUI_INSTALLOPTIONS_READ $R3 "pageInputLicenseInfo.ini" "Field 4" "State"
!insertmacro MUI_INSTALLOPTIONS_READ $R4 "pageInputLicenseInfo.ini" "Field 5" "State"
!insertmacro MUI_INSTALLOPTIONS_READ $R5 "pageInputLicenseInfo.ini" "Field 6" "State"
nsExec::ExecToStack '$INSTDIR\ParamterTestConsole.exe ${PRODUCT_NAME} $R0 $R1$R2$R3$R4$R5'
Pop $2 ; Exit code
Pop $3 ; console OUTPUT
Blah blah..........
FunctionEnd
NSIS INI File:
; Ini file generated by the HM NIS Edit IO designer.
[Settings]
NumFields=14
Title=test
[Field 1]
Type=Text
Text=1
Left=29
Right=275
Top=46
Bottom=57
[Field 2]
Type=Text
Text=123
Left=30
Right=60
Top=67
Bottom=78
[Field 3]
Type=Text
Text=123
Left=74
Right=103
Top=67
Bottom=78
[Field 4]
Type=Text
Text=123
Left=121
Right=149
Top=67
Bottom=78
[Field 5]
Type=Text
Text=123
Left=164
Right=193
Top=67
Bottom=78
[Field 6]
Type=Text
Text=123
Left=206
Right=236
Top=67
Bottom=78
[Field 7]
Type=Label
Text=IP
Left=1
Right=15
Top=48
Bottom=56
[Field 8]
Type=Label
Text=Key
Left=1
Right=20
Top=70
Bottom=78
[Field 9]
Type=Button
Text=enter
Flags=NOTIFY
Left=225
Right=275
Top=92
Bottom=105
[Field 10]
Type=Label
Text=※
Enter four digits.
Left=0
Right=152
Top=26
Bottom=43
[Field 11]
Type=Label
Text=-
Left=154
Right=160
Top=68
Bottom=80
[Field 12]
Type=Label
Text=-
Left=199
Right=205
Top=68
Bottom=76
[Field 13]
Type=Label
Text=-
Left=110
Right=116
Top=68
Bottom=76
[Field 14]
Type=Label
Text=-
Left=64
Right=70
Top=68
Bottom=76
Please help me.

Answer 1

As mentioned in the documentation, you can make use of the MaxLen option.
Example:
[Field 1]
Type=Text
Text=1
Left=29
Right=275
Top=46
Bottom=57
MaxLen=4