Dynamic Date Params in API Query String

[djanszentql]

I have 2 parameters/query strings in my API call that are sDate and eDate.  I need to set sDate dynamically to be TODAY()-90 to get the last 3 months of data.

My api call currently looks like this:

...&sDate="&Text.Replace(Date.AddDays(Date.From(DateTime.LocalNow()), -90),", ","-")&"edate=2020-12-21...

The error message I receive is: 

Expression.Error: We cannot convert the value #date(2020, 9, 23) to type Text.
Details:
Value=9/23/2020
Type=[Type]

I tried wrapping the Date.From in a Date.ToText function, but when I do that the API returns nothing.  Is there a test environment or way I can see what the variable looks like as I write my code in M?  It is very difficult to decipher when there is no debugging option.  Thanks!

[djanszentql · Accepted solution]

Solution: 

Date.ToText(Date.AddDays(Date.From(DateTime.LocalNow()), -10),"yyyy-MM-dd")

[lbendlin]

Do your conversion the other way round - use Text.From()

Here's a website that allows you to test API calls:  Online API Testing Tool | Test Your API Online (reqbin.com)

[djanszentql]

I just posted the solution.  Also, it wasn't the API call I was testing, but rather the M formula within the API call.