is there a code that can fix my current code? - excel

Question

I've created a check-in / check-out system. my code works perfectly fine when applied to only one sheet. but when I try to apply this code to multiple sheets, I get error, I've tried three codes and still cant get excel to apply the code to each separate sheet. Any code I use, confuses excel and redirects me to the first sheet.
1st code I used
dim WS as worksheet
for each WS in sheets
(my code)
next WS
2nd code I used
For Each Worksheet In ThisWorkbook.worksheets
sheets("may","June","july").activate
(my code)
next worksheet
ive also tried, (worksheet.activate) but this code redirects me to the first sheet and losses the data on other sheets
Here's the current code I'm trying to get to work
Sub Check_in()
For Each Worksheet In ThisWorkbook.worksheets
worksheets("April", "May", "June").Activate
Dim code As String: code = InputBox("Please scan a barcode", "Scan procedure")
If code = "" Then MsgBox ("No code scanned"): Exit Sub
Dim NbChIn As Integer: NbChIn = application.CountIf(Range("STORE_RECORDS [CHECKED OUT on its way to analytical lab]"), code)
Dim NbChOut As Integer: NbChOut = application.CountIf(Range("STORE_RECORDS[SAMPLE RECEIVED from analytical lab]"), code)
If NbChIn > NbChOut And NbChIn > 0 Then
MsgBox ("This sample is already Checked-out" & Chr(10) & "Please click sample received and retry"): Exit Sub
Else
Cells(Rows.Count, 1).End(xlUp).Offset(1, 0) = code
Cells(Rows.Count, 1).End(xlUp).Offset(0, 1) = Now
End If
Next Worksheet
End Sub
Sub Check_Out()
Dim code As String: code = InputBox("Please scan a barcode", "Scan procedure")
If code = "" Then MsgBox ("No code scanned"): Exit Sub
Dim NbChIn As Integer: NbChIn = application.CountIf(Range("STORE_RECORDS[CHECKED OUT on its way to analytical lab]"), code)
Dim NbChOut As Integer: NbChOut = application.CountIf(Range("STORE_RECORDS[SAMPLE RECEIVED from analytical lab]"), code)
If NbChIn = NbChOut And NbChIn > 0 Then
MsgBox ("This sample has already been received" & Chr(10) & "Please check it out and retry"): Exit Sub
Else
If Range("STORE_RECORDS[CHECKED OUT on its way to analytical lab]").Find(code, , , xlWhole, , xlPrevious) Is Nothing Then MsgBox ("No match, ask Carlos !"): Exit Sub
Range("STORE_RECORDS[CHECKED OUT on its way to analytical lab]").Find(code, , , xlWhole, , xlPrevious).Offset(0, 2) = code
Range("STORE_RECORDS[CHECKED OUT on its way to analytical lab]").Find(code, , , xlWhole, , xlPrevious).Offset(0, 3) = Now
End If
End Sub'
code usually says wrong number of arguments, or object doesn't support this property or method. code only works on sheet 1 or in my case (April) I want this code to apply to each sheet, organized by months.