EnvelopeGenerator/EnvelopeGenerator.Web/Controllers/Test/TestCacheController.cs

using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Caching.Distributed;

namespace EnvelopeGenerator.Web.Controllers.Test
{
    [Route("api/[controller]")]
    [ApiController]
    public class TestCacheController : ControllerBase
    {
        private readonly IDistributedCache _cache;

        public TestCacheController(IDistributedCache cache)
        {
            _cache = cache;
        }

        [HttpPost]
        public async Task<IActionResult> SetCacheAsync(string key, string value)
        {
            var options = new DistributedCacheEntryOptions()
                .SetAbsoluteExpiration(TimeSpan.FromMinutes(5));

            await _cache.SetStringAsync(key, value, options);

            return Ok();
        }

        [HttpGet]
        public async Task<IActionResult> GetCacheAsync(string key)
        {
            var value = await _cache.GetStringAsync(key);
            return value is null ? BadRequest() : Ok(value);
        }
    }
}